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68 Cards in this Set
- Front
- Back
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What is the Polarity of Water?
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H+ and O-
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What is a hydrogen bond?
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A bond between the positive pole of Water and the Negative Pole of another molecule
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What is cohesion? (In water)
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Makes water molecules stick together because of hydrogen bonds.
Pulling forces can be exerted to carry water to the tops of trees. |
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What does a 'transport medium' mean?
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Water is used to transpire nutrients etc. inside for example a tree
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What are solvent properties?
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How substances dissolve due to polarity.
Inorganic particles with positive or negative charges Organic substances with polar molecules Enzymes |
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What is the 'heat capacity' of water?
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High. This means that large amounts of heat are needed to change its temperature. Energy is needed to break hydrogen bonds.
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What is the boiling point of water?
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100 degrees celcius.
Needs to be liquid to act as a medium for metabolic reactions. |
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What is the cooling effect and evaporation of water?
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Evaporate at temperatures below boiling point.
Evaporation cools down water. Water can be used as a coolant. |
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Four most common chemical elements?
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Carbon. Hydrogen, Oxygen and Nitrogen
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What is Sulphur? (S)
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Needed to make two of twenty amino acids
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What is Calcium? (Ca)
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Acts as a messenger, binding proteins that regulate processes within cells.
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What is Phosphorus? (P)
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Part of the phosphate groups in ATP and DNA.
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What is Iron? (Fe)
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Needed to make cytochromes - proteins used fro electron transport.
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What is Sodium? (Na)
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Pumped into the cytoplasm to raise the solute concentration and catalyze osmosis.
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What is an organic compound?
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Compounds containing Carbon that are found in living organisms.
(Excluding Carbon Dioxide, Carbonates and Hydrogen Carbonates) |
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What are inorganic compounds?
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Compounds that do not contain carbon.
Mostly Carbohydrates, Lipids and Proteins. |
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What is a macromolecule?
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A large organic compound.
Built from smaller subunits. |
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What is condensation?
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Joining two molecules together to form a larger molecule by peptide linkages.
Makes: di- and polysaccharides di- and polypeptides. di- and triglycerides |
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What is hydrolysis?
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Breaks macromolecules apart, uses water molecules made in condensation.
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What is a monosaccharide?
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Glucose, Galactose and Fructose
Simple sugar |
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What is a disaccharide?
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Maltose, Lactose and Sucrose
Complex Sugar |
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What is a polysaccharide?
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Starch, Glycogen and Cellulose
Complex sugar |
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What are lipids?
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Lipids are fats. They help with energy storage, heat insulation and buoyancy.
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What are the advantages of lipid as energy storage?
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More energy per gram of fat
Insoluble to water, do not cause problems with osmosis. |
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What are the advantages of carbohydrates as energy storage?
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Easily digested, quick energy release.
Soluble to water, easier to transport |
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What are nucleotides?
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Subunits of DNA.
Made of a sugar (deoxyribose) a phosphate grow and a base. Can link together (sugar --> phosphate) to create strings of nucleotides. |
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What are the bases of DNA?
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A, C, G, T
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What is a double helix?
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Two strands of Nucelotides linked together by hydrogen bonds between the bases of the nucleotides.
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What is complementary base pairing?
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The way the bases pair together in DNA
A to T G to C |
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What does semi-conservative DNA replication mean?
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That each molecule formed consists of a a new strand and an old strand from the parent DNA molecule.
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What enzymes are involved in DNA Replication?
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DNA Polymerase and Helicase.
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How many different amino acids are there?
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20
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What are polypeptides?
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Long chains of amino acids
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What is RNA?
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Single stranded chain of nucleotides.
Sugar (Ribose), phosphate and base Bases A, C, G, and U |
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What is RNA?
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A copy of the DNA of the genes that holds the "recipe" for making polypeptides.
Bonds: A to U C to G |
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What is mRNA?
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The form of RNA that takes the RNA from the double helix to the ribose.
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What is RNA Polymerase?
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The enzyme that opens the double helix up to transcription.
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What is transcription?
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The process of copying the DNA into RNA for translation.
Moves from right to left on the top strand. |
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What is a codon?
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A group of three bases that codes for an amino acid.
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What is a ribosome?
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The facility that does translation. Made of a small and large subunit. The mRNA goes into the small subunit, moving left to right.
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What is tRNA?
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Transfer RNA is present round the ribosome. Binds to the ribosome and carries anticodons that carries the amino acid with the codon for this.
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What does 'one gene - one polypeptide hypothesis' mean?
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That one gene codes for one, and only one, polypeptide.
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What are catalysts?
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Structures that speed up chemical reactions without being changed themselves.
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What are enzymes?
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Globular proteins which acts as a catalysts of chemical reactions.
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What is denaturation?
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Changing the structure of an enzyme (or other protein) so that it can no longer carry out its function.
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What is a substrate?
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A reactant that is converted into a product.
Enzymes are substrate-specific. |
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What is an active site?
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An active site is a region on the surface of an enzyme to which substrates bind and which catalyses a chemical reaction involving the substrates.
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What is the effect of substrate concentration on enzyme activity?
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At low concentrations enzyme activity increases steeply.
At high substrate concentrations the increase slows as the active sites are all occupied. |
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What is the effect of temperature on enzyme activity?
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Activity increases as the temperature rises.
At high temperatures enzymes denature. |
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What is the effect of pH on enzyme activity?
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All enzymes have an optimum pH at which they function best, so activity is rising until they meet this point. After this point acids and alkalis denature enzymes.
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What is ATP?
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Energy. Called Adenosine Triphosphate.
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What is Cell Respiration?
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Controlled release of energy, in the form of ATP, form organic compounds in cells.
Can be aerobic and anaerobic. |
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What is the role of Glucose in Cell Respiration?
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It is broken down into pyruvate for small amounts of ATP.
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What is Anaerobic cell respiration?
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Cell respiration without oxygen.
Pyruvate remains in the cell and is converted into lactic acid. Does not produce ATP. Produces ethanol and carbon dioxide in yeast. |
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What is aerobic respiration?
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Pyruvate is absorbed by mitochondrion and broken into carbon dioxide and water. A large amount of ATP is released.
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What is photosynthesis?
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The process used by plants to produce their own organic substances using light energy and simple inorganic substances.
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What energy is converted in Photosynthesis?
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Light energy into chemical energy
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What absorbs light in Photosynthesis?
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The pigment Chlorophyll.
More red and blue light is absorbed that green. |
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What is the energy absorbed by chlorophyll used for in Photosynthesis?
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Production of ATP and photolysis.
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What is photolysis?
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Splitting of water molecules in Photosynthesis.
Results in formation of oxygen and hydrogen. Oxygen is a waste product. |
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What is absorbed in Photosynthesis?
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Carbon Dioxide is absorbed. Carbon is used to make organic substances.
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What is carbon fixation?
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The use of hydrogen from photolysis and energy from ATP.
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How do you measure uptake of carbon dioxide by Photosynthesis?
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Carbon dioxide can be absorbed from the water. More CO2 makes the the pH rise.
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How do you measure production of oxygen by Photosynthesis?
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Submerging the plant in water an measuring the volume of the bubbles
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How do you measure increase in biomass by Photosynthesis?
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Harvesting batches of plants at different times determines the mass of the plants and thus the rate of photosynthesis.
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What is the effect of Light intensity on Photosynthesis?
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At low to medium light the rate is directly proportional to the intensity.
At high light intensity the rate reaches a plateau. |
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What is the effect of CO2 concentration on Photosynthesis?
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No photosynthesis at low concentrations.
Increasing CO2 concentrations increases rate of reaction until it reaches a plateau. |
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What is the effect of temperature on Photosynthesis?
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As temperature increases, the rate increases steeply until reaching an optimum temperate. Above the optimum temperature the rate declines steeply.
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