Metabolism Flashcards
(44 cards)
What is metabolism and why does it occur?
-Chemical reactions that take place in cells, and therefore in the organism of which the cells are part of
-Keeps the organism alive
-Concerned with maintaining a balance between energy release and energy utilisation
What 2 types of chemical reactions is Metabolism made up of?
-Catabolic
-Anabolic
What is ‘Catabolic Metabolism (Catabolism)’?
The reactions in which large molecules are broken down to smaller ones (catabolism), e.g. digestion
-Release energy
What is ‘Anabolic Metabolism (Anabolism)’?
The reactions in which small molecules are built up into larger ones (anabolism), e.g. protein synthesis
-Require energy
What is a ‘Nurtient’?
Any susbatance in food that is used for growth, repair or maintaining the body; that is, any substance required for metabolism
Name the 6 groups of nutrients?
-Water
-Carbohydrates
-Lipids
-Proteins
-Minerals
-Vitamins
What is an ‘Organic Compound’?
Molecules that have a carbon chain. They also contain a number of hydrogen atoms and can include atoms of oxygen, nitrogen or sulfur.
What are ‘Carbohydrates’?
-Main source of energy for cells
-Simple sugars (monosaccharides), particularly glucose, are used in cellular respiration to release energy
-Simple sugars can join together tof orm larger molecules (disaccharides)
-Complex carbohydrates, such as starch, are broken down to simple sugars
-All contain atoms of carbon, hydrogen and oxygen
-Polysaccharides are larger carbohydrate molecyles formed when many simple sugards join together
What are ‘Lipids’?
-Include fats and oil (broken down into fatty acids and glycerol)
-Important source of energy
-Gylcerol is broken down to release energy in a similar way to glucose
-Each lipid molecule consists of glycerol and one, two or three fatty acid molecules
What are ‘Proteins’?
-Organic compounds that are made up of many amindo acids (an amino acid is a molecule that contains an amino group and a carboxylic acid group)
-Two amindo acids bond together forming a peptide bond, releasing a water molecule
-20 different amino acids found in proteins, each one differening in the structure of the side chain
-Proteins consist of 100 or more amino acids; their type and order are determined by DNA, each protein has a characteristic shape due to the folding of the chain
-Shorter lengths of amino acids include dipeptides and polypetides
Name two other organic compounds (nucleic acids)
-Ribonucleic Acid (RNA)
-DNA
What are ‘Inorganic Compounds’?
-Not based on a carbon chain
-Do not contain carbon atoms, but those that do (e.g. CO2) are small molecules
Why is ‘Water’ important in metabolism?
-It is the fluid in which other substances are dissolved
-Some cellular chemical reactions occur in water
-Some water molecules take part in chemical reactions
Why are ‘Minerals’ important for metabolism?
-They may be part of enzymes
-Function as cofactors for enzymes
-Be part of substances such as adenosine triphosphate (ATP) that are involved in metabolism
Why are ‘Vitamins’ important in metabolism?
Act as coenzymes for many of the chemical reactions of metabolism
What are ‘Enzymes’?
-Biological catalysts that are able to speed up chemical reactions by lowering activation energy
-Not consumed or altered in reactions
What is the molecule called on which an enzyme acts?
Substrate - each enzyme will combine wuth only one particular substrate so is involved in only one specific reaction
What is the part of the enzyme molecule that combine the substrate and enzyme?
Active site
When the enzyme and substrate are combined, what are they called?
Enzyme-substrate complex
Whata re the two models to describe enzyme action?
-Lock and key model
-Induced fit model
What is the ‘Lock and Key Model’?
States that shape of the enzyme (they key) is always complementary to the shape of the substrate (the lock). Therefore, the two will fit exactolyt to form the enzyme-substrate complex.
What is the ‘Induced Fit Model’?
States that when the enzyme and substrate jon, they form weak bonds that cause the shape of the enzyme to change, creating complementary shapes
How does the concentration of an enzyme affect acivity?
The higher the concentration of an enzyme, the faster the rate of a chemical reaction becuase there are more enzyme molecules to influence reactants
-Body is able to regulate type and number of enzymes to contro, which reactions occyr and the rate at which they proceed
Why do the products of a reaction need to be continually removed?
To ensure the rate of reaction stays fast as it will become slower as it is more difficult for the substrate molecules to make contact with the enzyme molecules if there is more product
