Title
Demonstrate understanding of life processes at the cellular level
Date version published
17 November 2011
This achievement standard involves demonstrating understanding of life processes at the cellular level.
Achievement Criteria:
Achievement
· Demonstrate understanding of life processes at the cellular level.
Achievement with Merit
· Demonstrate in-depth understanding of life processes at the cellular level.
Achievement with Excellence
· Demonstrate comprehensive understanding of life processes at the cellular level.
Explanatory Notes
1 This achievement standard is derived from The New Zealand Curriculum, Learning Media, Ministry of Education, 2007, Level 7. It is aligned with the following achievement objective in the Living World strand:
Life Processes
· Explore the diverse ways in which animals and plants carry out the life processes and is related to the material in the Teaching and Learning Guide for Biology, Ministry of Education, 2010 at http://seniorsecondary.tki.org.nz.
2 Demonstrate understanding involves defining, using annotated diagrams or models to describe, and describing characteristics of, or providing an account of, life processes at the cellular level.
Demonstrate in-depth understanding involves using biological ideas to give reasons how or why life processes occur at the cellular level.
Demonstrate comprehensive understanding involves linking biological ideas about life processes at the cellular level. The discussion of ideas may involve justifying, relating, evaluating, comparing and contrasting, analysing.
3 Life processes at the cellular level include:
· photosynthesis
· respiration
· cell division (DNA replication and mitosis as part of the cell cycle).
4 Biological ideas, as they relate to each of the life processes at the cellular level, are selected from:
· movement of materials (including diffusion, osmosis, active transport)
· enzyme activity (specific names of enzymes are not required)
· factors affecting the process
· details of the processes only as they relate to the overall functioning of the cell (specific names of stages are not required)
· reasons for similarities and differences between cells such as cell size and shape, and type and number of organelles present.
5 Cells include plant cells and animal cells.
6 Assessment Specifications for this achievement standard can be accessed through the Biology Resources page found at http://www.nzqa.govt.nz/qualifications-standards/qualifications/ncea/subjects/.
Key Words: These are the words that you are expected to understand when used in questions and be able to use in your answers.
Core Vocabulary & Glossary:
· Activation Energy - the minimum quantity of energy which the reacting species must possess in order to undergo a specified reaction.
· Active Site - the part of an enzyme at which catalysis of the substrate occurs.
· Active Transport - he movement of a chemical substance through a gradient of concentration or electrical potential in the direction opposite to normal diffusion, requiring the expenditure of energy: active transport across a cell membrane.
· Adenine - A purine base, C5H5N5, that is the constituent involved in base pairing with thymine in DNA and with uracil in RNA.
· ADP - A nucleotide, C10H15N5O10P2, composed of adenosine and two linked phosphate groups, that is converted to ATP for the storage of energy.
· Aerobic - Occurring in the presence of oxygen or requiring oxygen to live. In aerobic respiration, which is the process used by the cells of most organisms, the production of energy from glucose metabolism requires the presence of oxygen.
· Anaerobic - Occurring in the absence of oxygen or not requiring oxygen to live. Anaerobic bacteria produce energy from food molecules without the presence of oxygen.
· ATP - adenosine triphosphate: a nucleotide that is the primary source of energy in all living cells because of its function in donating a phosphate group during biochemical activities; composed of adenosine, ribose, and three phosphate groups and formed by enzymatic reaction from adenosine diphosphate and an orthophosphate.
· Catalyst - substance that starts or speeds up a chemical reaction while undergoing no permanent change itself. The enzymes in saliva, for example, are catalysts in digestion.
· Cell Membrane - the thin membrane that forms the outer surface of the protoplasm of a cell and regulates the passage of materials in and out of the cell. It is made up of proteins and lipids and often contains molecular receptors. The membranes of organelles within the cell are made of the same basic material as the cell membrane. In plant cells, the cell membrane is surrounded by a rigid cell wall. Also called plasma membrane.
· Cell Wall - the rigid outermost cell layer found in plants and certain algae, bacteria, and fungi but characteristically absent from animal cells.
· Cellular Respiration - the series of metabolic processes by which living cells produce energy through the oxidation of organic substances.
· Centriole - either of a pair of cylinder-shaped bodies found in the centrosome of most eukaryotic organisms other than plants. During cell division (both mitosis and meiosis), the centrioles move apart to help form the spindle, which then distributes the chromosomes in the dividing cell.
· Chloroplast - a plastid containing chlorophyll and other pigments, occurring in plants and algae that carry out photosynthesis.
· Coding strand - is the DNA strand which has the same base sequence as the RNA transcript produced (although with thymine replaced by uracil). It is this strand which contains codons, while the non-coding strand contains anti codons.
· Co-Enzyme - a loosely bound co-factors to an enzyme.
· Co-Factor - is a non-protein chemical compound that is bound to a protein and is required for the protein's biological activity. These proteins are commonly enzymes, and co-factors can be considered "helper molecules" that assist in biochemical transformations.
· Concentration Gradient - gradual increase or decrease of concentration across the solution.
· Cristae - (singular crista) are the internal compartments formed by the inner membrane of a mitochondrion.
· Cytosine - is one of the four main bases found in DNA and RNA, it is a pyrimidine nitrogen base.
· Denatured - a structural change in macromolecules caused by extreme conditions, such as high temperature (e.g. proteins).
· Diffusion - the passive movement of molecules or particles along a concentration gradient, or from regions of higher to regions of lower concentration.
· DNA - deoxyribonucleic acid, a self-replicating material which is present in nearly all living organisms as the main constituent of chromosomes. It is the carrier of genetic information.
· DNA ligase - is a specific type of enzyme, a ligase, that facilitates the joining of DNA strands together by catalyzing the formation of a phosphodiester bond.
· DNA polymerase - the enzyme responsible for DNA replication
· Double Helix - the coiled structure of double-stranded DNA in which strands linked by hydrogen bonds form a spiral configuration, with the two strands oriented in opposite directions.
· Endoplasmic Reticulum - an extensive intracellular membrane system whose functions include synthesis and transport of lipids and, in regions where ribosomes are attached, of proteins.
· Enzyme - any of a group of complex proteins or conjugated proteins that are produced by living cells and act as catalysts in specific biochemical reactions.
· Enzyme Inhibitors - are molecules, which bind to enzymes and decreases their activity.
· Fermentation - is a metabolic process converting sugar to acids, gases and/or alcohol using yeast or bacteria. In its strictest sense, fermentation is the absence of the electron transport chain and takes a reduced carbon source, such as glucose, and makes products like lactic acid or acetate. No oxidative phosphorylation is used, which yields a much lower amount of ATP.
· Flaccid - (of plant tissue) drooping or inelastic through lack of water.
· Glycolysis - is the metabolic pathway that converts glucose C6H12O6, into pyruvate, CH3COCOO− + H+. The free energy released in this process is used to form the high-energy compounds ATP (adenosine triphosphate) and NADH (reduced nicotinamide adenine dinucleotide). Glycolysis is a purely anaerobic reaction.
· Golgi Apparatus - packages proteins inside the cell before they are sent to their destination; it is particularly important in the processing of proteins for secretion.
· Grana - (singular: granum), thylakoid stacks in chloroplasts.
· Guanine - is one of the four main nucleobases found in the nucleic acids DNA and RNA. In DNA, guanine is paired with cytosine. With the formula C5H5N5O, guanine is a derivative of purine.
· Helicase - any of the enzymes that use the energy derived from the hydrolysis of ATP to unwind the double-stranded helical structure of nucleic acids.
· Induced Fit Model - a model to suggest a mode of action of enzymes in which the substrate binds to the active site of the protein, causing a conformational change in the protein.
· Ion Exchange Pump - a complex of proteins located in the cell membrane that is responsible for actively transporting ions across the membrane against a concentration gradient using energy rich ATP molecules. Functions in maintaining osmotic balance in cells and in the conduction of nerve impulses.
· Krebs Cycle - a cyclic series of biochemical reactions, usually in the mitochondria, that represents the final common pathway in all aerobic organisms for the oxidation of amino acids, fats, and carbohydrates, and that converts the citric acid, etc. from food into carbon dioxide and ATP.
· Lactic acid - a three-carbon organic acid produced by anaerobic respiration.
· Lagging strand - in DNA replication, the strand in which the nascent strand is synthesized in discontinuous segments after the other or leading strand. See also Okazaki fragments.
· Lamellae - a thin leaf or plate structure.
· Leading strand - in DNA replication, the strand that is copied continuously.
· Light Dependent Phase - the first stage of photosynthesis, occurring only in the presence of light, during which energy captured from light drives the production of ATP.
· Light Independent Phase - of photosynthesis are chemical reactions that convert carbon dioxide and other compounds into glucose. These reactions occur in the stroma, the fluid-filled area of a chloroplast outside of the thylakoid membranes.
· Lipid Bilayer - also known as the phospholipid bilayer, is a sheet of lipids two molecules thick, arranged so that the hydrophilic phosphate heads point “out” to the water on either side of the bilayer and the hydrophobic tails point “in” to the core of the bilayer.
· Lock And Key Theory - A model for enzyme-substrate interaction suggesting that the enzyme and the substrate possess specific complementary geometric shapes that fit exactly into one another. Like a key into a lock, only the correct size and shape of the substrate (the key) would fit into the active site (the key hole) of the enzyme (the lock).
· Lysosomes - are cellular organelles that contain acid hydrolase enzymes that break down waste materials and cellular debris. They can be described as the stomach of the cell. They are found in animal cells, while their existence in yeasts and plants is disputed.
· Mitochondria - a membrane-enclosed structure found in most eukaryotic cells that performs cellular respiration.
· Mitosis - is the process by which a cell, which has previously replicated each of its chromosomes, separates the chromosomes in its cell nucleus into two identical sets of chromosomes, each set in its own new nucleus.
· Nuclear Membrane - is the double lipid bilayer membrane which surrounds the genetic material and nucleolus in eukaryotic cells.
· Nucleolus - is a non-membrane bound structure found in the nucleus of cells. It is composed of proteins and nucleic acids found within the nucleus of eukaryotic cells. Its function is to transcribe ribosomal RNA (rRNA) and assemble it within the cell.
· Nucleotides - are biological molecules that form the building blocks of nucleic acids (DNA and RNA) and serve to carry packets of energy within the cell (ATP).
· Nucleus - the control center of a cell, containing the cell's chromosomal DNA.
· Organelles - is a specialized subunit within a cell that has a specific function, and it is usually separately enclosed within its own lipid bilayer.
· Osmosis - is the spontaneous net movement of solvent molecules through a partially permeable membrane into a region of higher solute concentration, in the direction that tends to equalize the solute concentrations on the two sides.
· Passive transport - is a movement of biochemicals and other atomic or molecular substances across membranes. Unlike active transport, it does not require an input of chemical energy.
· Phagocytosis - the ingestion of a smaller cell or cell fragment, a microorganism, or foreign particles by means of the local infolding of a cell's membrane and the protrusion of its cytoplasm around the fold until the material has been surrounded and engulfed by closure of the membrane and formation of a vacuole: characteristic of amebas and some types of white blood cells.
· Photosynthesis - the complex process by which carbon dioxide, water, and certain inorganic salts are converted into carbohydrates by green plants, algae, and certain bacteria, using energy from the sun and chlorophyll.
· Pinocytosis - the transport of fluid into a cell by means of local infoldings by the cell membrane so that a tiny vesicle or sac forms around each droplet, which is then taken into the interior of the cytoplasm.
· Plasmolysis - contraction of thecytoplasm in a living cell when water is removed by osmosis.
· Ribosome - a tiny, somewhat mitten-shaped organelle occurring in great numbers in the cell cytoplasm either freely, in small clusters, or attached to the outer surfaces of endoplasmic reticula, and functioning as the site of protein manufacture.
· RNA primer - is a strand of nucleic acid that serves as a starting point for DNA synthesis. In most cases of natural DNA replication, the primer for DNA synthesis and replication is a short strand of RNA.
· Semi-Permeable Membrane - is a membrane that will allow certain molecules or ions to pass through it by diffusion and occasionally specialized "facilitated diffusion".
· Stroma - the fluid in between grana, where carbohydrate-formation reactions occur in the chloroplasts of plant cells photosynthesizing.
· Substrate - a molecule that is acted upon by an enzyme.
· Surface Area : Volume Ratio - is the amount of surface area per unit volume of an object or collection of objects.
· Template strand - the non-coding strand of a DNA molecule that is used as a template for RNA synthesis.
· Thymine - a pyrimidine base, C 5 H 6 N 2 O 2 , that is one of the principal components of DNA, in which it is paired with adenine.
· Turgor - the normal rigidity of plant cells, resulting from the pressure exerted by the cell contents on the cell walls.
· Uracil - a pyrimidine base, C 4 H 4 N 2 O 2 , that is one of the fundamental components of RNA.
· Vacuole - a membrane-bound cavity within a cell, often containing a watery liquid or secretion.
· Vesicle - A membrane-bound compartment found in a cell.
At the end of this unit of work you should be able to use the core knowledge listed in the statements below to describe, explain and discuss aspects of cell structure and function. Questions may be presented to you in novel or applied situations that will require you to recognise and link these ideas together.
1. Recognise the cell as the basic unit of living things.
2. Describe the structure of a generalised plant and animal cell and describe the functions of the cellular components and organelles.
3. Identify the similarities and differences between plant and animal cells
4. Explain reasons for similarities and differences in cell shapes, sizes, relative number of organelles and internal structure between plant and animal cells.
5. Explain how substances move in and out of cells by passive and active transport.
6. Describe the role of enzymes in cell processes and explain how they work.
7. Describe factors which affect enzyme activity (temp, pH, enzyme and substrate concentration, inhibitors)
8. Summarise the process of respiration and understand that it is controlled by enzymes
9. Link the structure and function of the mitochondria
10. Summarise the process of photosynthesis and understand that it is controlled by enzymes
11. Link the structure and function of the chloroplasts and its location in the leaf
12. Describe factors which affect the rate of photosynthesis (temp, light intensity, wavelength, CO2)
13. Describe the structure of DNA and the process of DNA replication.
14. Describe the purpose of mitosis and factors affecting the rate of mitosis.
15. Communicate ideas clearly and succinctly using the biological language relevant to this topic.
Demonstrate understanding of life processes at the cellular level
Date version published
17 November 2011
This achievement standard involves demonstrating understanding of life processes at the cellular level.
Achievement Criteria:
Achievement
· Demonstrate understanding of life processes at the cellular level.
Achievement with Merit
· Demonstrate in-depth understanding of life processes at the cellular level.
Achievement with Excellence
· Demonstrate comprehensive understanding of life processes at the cellular level.
Explanatory Notes
1 This achievement standard is derived from The New Zealand Curriculum, Learning Media, Ministry of Education, 2007, Level 7. It is aligned with the following achievement objective in the Living World strand:
Life Processes
· Explore the diverse ways in which animals and plants carry out the life processes and is related to the material in the Teaching and Learning Guide for Biology, Ministry of Education, 2010 at http://seniorsecondary.tki.org.nz.
2 Demonstrate understanding involves defining, using annotated diagrams or models to describe, and describing characteristics of, or providing an account of, life processes at the cellular level.
Demonstrate in-depth understanding involves using biological ideas to give reasons how or why life processes occur at the cellular level.
Demonstrate comprehensive understanding involves linking biological ideas about life processes at the cellular level. The discussion of ideas may involve justifying, relating, evaluating, comparing and contrasting, analysing.
3 Life processes at the cellular level include:
· photosynthesis
· respiration
· cell division (DNA replication and mitosis as part of the cell cycle).
4 Biological ideas, as they relate to each of the life processes at the cellular level, are selected from:
· movement of materials (including diffusion, osmosis, active transport)
· enzyme activity (specific names of enzymes are not required)
· factors affecting the process
· details of the processes only as they relate to the overall functioning of the cell (specific names of stages are not required)
· reasons for similarities and differences between cells such as cell size and shape, and type and number of organelles present.
5 Cells include plant cells and animal cells.
6 Assessment Specifications for this achievement standard can be accessed through the Biology Resources page found at http://www.nzqa.govt.nz/qualifications-standards/qualifications/ncea/subjects/.
Key Words: These are the words that you are expected to understand when used in questions and be able to use in your answers.
Core Vocabulary & Glossary:
· Activation Energy - the minimum quantity of energy which the reacting species must possess in order to undergo a specified reaction.
· Active Site - the part of an enzyme at which catalysis of the substrate occurs.
· Active Transport - he movement of a chemical substance through a gradient of concentration or electrical potential in the direction opposite to normal diffusion, requiring the expenditure of energy: active transport across a cell membrane.
· Adenine - A purine base, C5H5N5, that is the constituent involved in base pairing with thymine in DNA and with uracil in RNA.
· ADP - A nucleotide, C10H15N5O10P2, composed of adenosine and two linked phosphate groups, that is converted to ATP for the storage of energy.
· Aerobic - Occurring in the presence of oxygen or requiring oxygen to live. In aerobic respiration, which is the process used by the cells of most organisms, the production of energy from glucose metabolism requires the presence of oxygen.
· Anaerobic - Occurring in the absence of oxygen or not requiring oxygen to live. Anaerobic bacteria produce energy from food molecules without the presence of oxygen.
· ATP - adenosine triphosphate: a nucleotide that is the primary source of energy in all living cells because of its function in donating a phosphate group during biochemical activities; composed of adenosine, ribose, and three phosphate groups and formed by enzymatic reaction from adenosine diphosphate and an orthophosphate.
· Catalyst - substance that starts or speeds up a chemical reaction while undergoing no permanent change itself. The enzymes in saliva, for example, are catalysts in digestion.
· Cell Membrane - the thin membrane that forms the outer surface of the protoplasm of a cell and regulates the passage of materials in and out of the cell. It is made up of proteins and lipids and often contains molecular receptors. The membranes of organelles within the cell are made of the same basic material as the cell membrane. In plant cells, the cell membrane is surrounded by a rigid cell wall. Also called plasma membrane.
· Cell Wall - the rigid outermost cell layer found in plants and certain algae, bacteria, and fungi but characteristically absent from animal cells.
· Cellular Respiration - the series of metabolic processes by which living cells produce energy through the oxidation of organic substances.
· Centriole - either of a pair of cylinder-shaped bodies found in the centrosome of most eukaryotic organisms other than plants. During cell division (both mitosis and meiosis), the centrioles move apart to help form the spindle, which then distributes the chromosomes in the dividing cell.
· Chloroplast - a plastid containing chlorophyll and other pigments, occurring in plants and algae that carry out photosynthesis.
· Coding strand - is the DNA strand which has the same base sequence as the RNA transcript produced (although with thymine replaced by uracil). It is this strand which contains codons, while the non-coding strand contains anti codons.
· Co-Enzyme - a loosely bound co-factors to an enzyme.
· Co-Factor - is a non-protein chemical compound that is bound to a protein and is required for the protein's biological activity. These proteins are commonly enzymes, and co-factors can be considered "helper molecules" that assist in biochemical transformations.
· Concentration Gradient - gradual increase or decrease of concentration across the solution.
· Cristae - (singular crista) are the internal compartments formed by the inner membrane of a mitochondrion.
· Cytosine - is one of the four main bases found in DNA and RNA, it is a pyrimidine nitrogen base.
· Denatured - a structural change in macromolecules caused by extreme conditions, such as high temperature (e.g. proteins).
· Diffusion - the passive movement of molecules or particles along a concentration gradient, or from regions of higher to regions of lower concentration.
· DNA - deoxyribonucleic acid, a self-replicating material which is present in nearly all living organisms as the main constituent of chromosomes. It is the carrier of genetic information.
· DNA ligase - is a specific type of enzyme, a ligase, that facilitates the joining of DNA strands together by catalyzing the formation of a phosphodiester bond.
· DNA polymerase - the enzyme responsible for DNA replication
· Double Helix - the coiled structure of double-stranded DNA in which strands linked by hydrogen bonds form a spiral configuration, with the two strands oriented in opposite directions.
· Endoplasmic Reticulum - an extensive intracellular membrane system whose functions include synthesis and transport of lipids and, in regions where ribosomes are attached, of proteins.
· Enzyme - any of a group of complex proteins or conjugated proteins that are produced by living cells and act as catalysts in specific biochemical reactions.
· Enzyme Inhibitors - are molecules, which bind to enzymes and decreases their activity.
· Fermentation - is a metabolic process converting sugar to acids, gases and/or alcohol using yeast or bacteria. In its strictest sense, fermentation is the absence of the electron transport chain and takes a reduced carbon source, such as glucose, and makes products like lactic acid or acetate. No oxidative phosphorylation is used, which yields a much lower amount of ATP.
· Flaccid - (of plant tissue) drooping or inelastic through lack of water.
· Glycolysis - is the metabolic pathway that converts glucose C6H12O6, into pyruvate, CH3COCOO− + H+. The free energy released in this process is used to form the high-energy compounds ATP (adenosine triphosphate) and NADH (reduced nicotinamide adenine dinucleotide). Glycolysis is a purely anaerobic reaction.
· Golgi Apparatus - packages proteins inside the cell before they are sent to their destination; it is particularly important in the processing of proteins for secretion.
· Grana - (singular: granum), thylakoid stacks in chloroplasts.
· Guanine - is one of the four main nucleobases found in the nucleic acids DNA and RNA. In DNA, guanine is paired with cytosine. With the formula C5H5N5O, guanine is a derivative of purine.
· Helicase - any of the enzymes that use the energy derived from the hydrolysis of ATP to unwind the double-stranded helical structure of nucleic acids.
· Induced Fit Model - a model to suggest a mode of action of enzymes in which the substrate binds to the active site of the protein, causing a conformational change in the protein.
· Ion Exchange Pump - a complex of proteins located in the cell membrane that is responsible for actively transporting ions across the membrane against a concentration gradient using energy rich ATP molecules. Functions in maintaining osmotic balance in cells and in the conduction of nerve impulses.
· Krebs Cycle - a cyclic series of biochemical reactions, usually in the mitochondria, that represents the final common pathway in all aerobic organisms for the oxidation of amino acids, fats, and carbohydrates, and that converts the citric acid, etc. from food into carbon dioxide and ATP.
· Lactic acid - a three-carbon organic acid produced by anaerobic respiration.
· Lagging strand - in DNA replication, the strand in which the nascent strand is synthesized in discontinuous segments after the other or leading strand. See also Okazaki fragments.
· Lamellae - a thin leaf or plate structure.
· Leading strand - in DNA replication, the strand that is copied continuously.
· Light Dependent Phase - the first stage of photosynthesis, occurring only in the presence of light, during which energy captured from light drives the production of ATP.
· Light Independent Phase - of photosynthesis are chemical reactions that convert carbon dioxide and other compounds into glucose. These reactions occur in the stroma, the fluid-filled area of a chloroplast outside of the thylakoid membranes.
· Lipid Bilayer - also known as the phospholipid bilayer, is a sheet of lipids two molecules thick, arranged so that the hydrophilic phosphate heads point “out” to the water on either side of the bilayer and the hydrophobic tails point “in” to the core of the bilayer.
· Lock And Key Theory - A model for enzyme-substrate interaction suggesting that the enzyme and the substrate possess specific complementary geometric shapes that fit exactly into one another. Like a key into a lock, only the correct size and shape of the substrate (the key) would fit into the active site (the key hole) of the enzyme (the lock).
· Lysosomes - are cellular organelles that contain acid hydrolase enzymes that break down waste materials and cellular debris. They can be described as the stomach of the cell. They are found in animal cells, while their existence in yeasts and plants is disputed.
· Mitochondria - a membrane-enclosed structure found in most eukaryotic cells that performs cellular respiration.
· Mitosis - is the process by which a cell, which has previously replicated each of its chromosomes, separates the chromosomes in its cell nucleus into two identical sets of chromosomes, each set in its own new nucleus.
· Nuclear Membrane - is the double lipid bilayer membrane which surrounds the genetic material and nucleolus in eukaryotic cells.
· Nucleolus - is a non-membrane bound structure found in the nucleus of cells. It is composed of proteins and nucleic acids found within the nucleus of eukaryotic cells. Its function is to transcribe ribosomal RNA (rRNA) and assemble it within the cell.
· Nucleotides - are biological molecules that form the building blocks of nucleic acids (DNA and RNA) and serve to carry packets of energy within the cell (ATP).
· Nucleus - the control center of a cell, containing the cell's chromosomal DNA.
· Organelles - is a specialized subunit within a cell that has a specific function, and it is usually separately enclosed within its own lipid bilayer.
· Osmosis - is the spontaneous net movement of solvent molecules through a partially permeable membrane into a region of higher solute concentration, in the direction that tends to equalize the solute concentrations on the two sides.
· Passive transport - is a movement of biochemicals and other atomic or molecular substances across membranes. Unlike active transport, it does not require an input of chemical energy.
· Phagocytosis - the ingestion of a smaller cell or cell fragment, a microorganism, or foreign particles by means of the local infolding of a cell's membrane and the protrusion of its cytoplasm around the fold until the material has been surrounded and engulfed by closure of the membrane and formation of a vacuole: characteristic of amebas and some types of white blood cells.
· Photosynthesis - the complex process by which carbon dioxide, water, and certain inorganic salts are converted into carbohydrates by green plants, algae, and certain bacteria, using energy from the sun and chlorophyll.
· Pinocytosis - the transport of fluid into a cell by means of local infoldings by the cell membrane so that a tiny vesicle or sac forms around each droplet, which is then taken into the interior of the cytoplasm.
· Plasmolysis - contraction of thecytoplasm in a living cell when water is removed by osmosis.
· Ribosome - a tiny, somewhat mitten-shaped organelle occurring in great numbers in the cell cytoplasm either freely, in small clusters, or attached to the outer surfaces of endoplasmic reticula, and functioning as the site of protein manufacture.
· RNA primer - is a strand of nucleic acid that serves as a starting point for DNA synthesis. In most cases of natural DNA replication, the primer for DNA synthesis and replication is a short strand of RNA.
· Semi-Permeable Membrane - is a membrane that will allow certain molecules or ions to pass through it by diffusion and occasionally specialized "facilitated diffusion".
· Stroma - the fluid in between grana, where carbohydrate-formation reactions occur in the chloroplasts of plant cells photosynthesizing.
· Substrate - a molecule that is acted upon by an enzyme.
· Surface Area : Volume Ratio - is the amount of surface area per unit volume of an object or collection of objects.
· Template strand - the non-coding strand of a DNA molecule that is used as a template for RNA synthesis.
· Thymine - a pyrimidine base, C 5 H 6 N 2 O 2 , that is one of the principal components of DNA, in which it is paired with adenine.
· Turgor - the normal rigidity of plant cells, resulting from the pressure exerted by the cell contents on the cell walls.
· Uracil - a pyrimidine base, C 4 H 4 N 2 O 2 , that is one of the fundamental components of RNA.
· Vacuole - a membrane-bound cavity within a cell, often containing a watery liquid or secretion.
· Vesicle - A membrane-bound compartment found in a cell.
At the end of this unit of work you should be able to use the core knowledge listed in the statements below to describe, explain and discuss aspects of cell structure and function. Questions may be presented to you in novel or applied situations that will require you to recognise and link these ideas together.
1. Recognise the cell as the basic unit of living things.
2. Describe the structure of a generalised plant and animal cell and describe the functions of the cellular components and organelles.
3. Identify the similarities and differences between plant and animal cells
4. Explain reasons for similarities and differences in cell shapes, sizes, relative number of organelles and internal structure between plant and animal cells.
5. Explain how substances move in and out of cells by passive and active transport.
6. Describe the role of enzymes in cell processes and explain how they work.
7. Describe factors which affect enzyme activity (temp, pH, enzyme and substrate concentration, inhibitors)
8. Summarise the process of respiration and understand that it is controlled by enzymes
9. Link the structure and function of the mitochondria
10. Summarise the process of photosynthesis and understand that it is controlled by enzymes
11. Link the structure and function of the chloroplasts and its location in the leaf
12. Describe factors which affect the rate of photosynthesis (temp, light intensity, wavelength, CO2)
13. Describe the structure of DNA and the process of DNA replication.
14. Describe the purpose of mitosis and factors affecting the rate of mitosis.
15. Communicate ideas clearly and succinctly using the biological language relevant to this topic.