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29 Cards in this Set
- Front
- Back
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Define metabolism
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Metabolism is the sum of the biochemical processes occurring within the cells of a living organism which are necessary to maintain life.
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How do the cells of a living organism obtain their energy?
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From nutrients from the external environment.
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What are the ultimate products of the oxidation of nutrients?
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Carbon dioxide and water.
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Name an energy transporter molecule. Why are these of ten referred to as energy 'currency'?
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ATP (adenosine triphosphate). These are often referred to as energy 'currency' as they provide a means for energy to be exchanged between energy-requiring processes.
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How do the homeostatic mechanisms in the living organism differ between the absorptive and post-absorptive phases?
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In the absorptive phase, the emphasis is on storage of excess energy. In the post-absorptive phase, the emphasis is on mobilisation of stored energy, as there is no supply of exogenous energy.
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Explain anabolism.
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Anabolism is the process of using energy to build complex structures from the organic nutrient molecules supplied in the diet. This primarily functions in storage - in a absorptive phase.
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Explain catabolism.
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Catabolism is the process of releasing energy via the breakdown of large, complex molecules into their smaller sub-units. Organic molecules are oxidised to water and carbon dioxide, releasing energy in the form of heat, but also in transporter molecules such as ATP.
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Name a monomer and the polymer it will produce after a condensation reaction. What other molecule will be produced?
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Other molecule: water.
Monosaccharides to polysaccharides Amino acids to protein Fatty acids to lipids Nucleotides to nucleic acids |
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What is the C:H:O ratio in a carbohydrate?
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1:2:1
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Give 3 uses for carbohydrates.
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Fuels, metabolic intermediates, energy stores, as a building block in the carbon skeleton.
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Name three types of lipids.
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Triglycerides.
Phospholipids. Steroids. |
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What is a triglyceride molecule composed of?
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3 fatty acids, 1 glycerol.
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What is a phospholipid molecule composed of?
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2 fatty acids, 1 glycerol, 1 phosphate group, 1 N-containing group
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What is a steroid molecule composed of?
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4 ring carbon skeleton, hydrocarbon functional groups.
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Name a very common fatty acid.
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Palmitic acid (C17?)
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Give 3 important functions of steroids.
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Cholesterol, as (some) hormones, bile acids.
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Give the functions of proteins. (7)
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Motor molecules.
Hormones. Enzymes. Receptor/signal molecules. Defence against infections. Transport molecules. Structural. |
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What is a generic amino acid composed?
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Carboxyl group, side chain, amino group.
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Give 3 ways in which amino acids can be classified.
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Ionic/not.
Acidic, basic, neutral. Polar/non-polar. |
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What is the name given to a substance/molecule which acts with an enzyme to all it to function?
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A co-enzyme.
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What is the significance of a committing enzyme?
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A committing enzyme catalyses steps common to all inputs. Thus, it has ultimate regulatory control over the reaction pathway.
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Give 4 examples of feedback which may regulate the concentration of a committing enzyme in a pathway?
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End product feedback. Co-enzyme product feedback. Hormones. Metabolites.
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Give an example of committing enzymes involved in a pathway.
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PFK and PEPK involved in glycolysis/gluconeogenesis.
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Briefly outline the processes of glycolysis and gluconeogenesis. Indicate the points of action of PFK and PEPK.
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Glucose - Glucose-6-Phosphate - Fructose-6-Phosphate - (PFK - phosphofructokinase) - Fructose-1,6-bisphosphate - Phosphoenolpyruvate - (PEPK - phosphoenolpyruvate carboxykinase) - Pyruvate.
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Give 3 potential co-enzymes of dehydrogenases.
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NAD
NADP FAD |
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What is the function of a carboxylase and what con-enzymes may it need to function?
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Add CO2; biotin, ATP.
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When transferring an amine, what coenzyme is needed by aminotransferase?
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Pyridoxal(P)
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What are the 3 basic components of a nucleotide?
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Nitrogenous base, 5 carbon sugar, phosphate.
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What are the two types of bases?
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Pyrimidines (1 ring - C,U,T) and purines (2 rings - A,G)
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