| metabolism def | all the chemical reactions that take place in the cell |
| catabolic metabolism and example | broken down to smaller molecules
releases atp
eg. digestion |
| anabolic reaction def and eg | built up to larger molecules
requires atp
eg. protein synthesis |
| maintains the balance between energy release and utilisation | metabolism |
| define nutrients | any substance in food that is used for growth, repair or maintaining the body. |
| six main groups of nutrients | water
carbohydrates
lipids
proteins
minerals
vitamins |
| organic compounds | have a carbon chain
have a number of hydrogen atoms, can also include oxygen, nitrogen, sulfur, dna and rna |
| carbohydrates | main source of energy for the cell
monosaccharides (mostly glucose) release energy
poly/disaccharides broken down before entering cell eg. starch
made of carbon, hydrogen, oxygen |
| organic compounds eg | carbohydrates, proteins, lipids |
| lipids | fats, oil and another important energy source
broken down to fatty acids and glycerol
contains one molecule of glycerol and 1-3 fatty acids
glycerol breaks down similar to glucose |
| proteins | made of amino acids
100 or more amino acids in a single protein
have characteristic shapes |
| essential amino acids | ones the body cant produce, so it must consume |
| amino acids | contain an amino group and a carboxylic acid group
20 different types found in proteins, each differing on structure of side chain.
2 bond to form a peptide bond
shorter ones are called dipeptides and polypeptides |
| inorganic compounds | not based on carbon chain
some reactions occur in water, some water takes part in the reaction |
| inorganic compounds egs | minerals
vitamins |
| minerals | may be part of enzymes, function as cofactors for enzymes or be a part of substances such as atp |
| vitamins | coenzymes for many chemical reactions of metabolism. |
| enzymes | biological catalysts used to speed up chemical reactions
react with one specific molecule |
| lock and key model | enzyme is always complementary to shape of substrate, therefore the two will fit exactly to form the enzyme substrate complex |
| induced fit model | when enzyme and substrate join, weak bonds are formed that change enzyme shape to create complementary shapes |
| factors affecting enzyme activity | shape and availability of active site
concentration of enzyme/substrate
temperature
pH levels |
| cofactors? | used by enzymes to change shape of active site, so that enzyme can combine with substrate.
eg. certain ions or non-proteins, minerals |
| cellular respiration def | the process by which organic molecules are broken down in the cells to release energy for cellular activity |
| cellular respiration can release energy from... | glucose, amino acids, fatty acids, glycerol |
