1.4 Proteins Flashcards
Give examples of different functions of proteins within an organism
The proteins within an organism function as
- Enzymes
- Hormones
- Receptors
- Antibodies
- Channel-forming proteins
- Carrier proteins
State the definition of an enzyme
An enzyme is a biological catalyst. Enzymes are found inside all living cells where they speed up chemical reactions while remaining unchanged themselves in the process
Define the terms ‘substrate’ and ‘product’ in an enzyme reaction
Substrate- Chemical substance at the start of a chemical reaction also known as the raw materials in the reaction
Product- Chemical substance made at the end of a chemical reaction
ENZYME
Substrate————- Product
Identify the type of chemical the enzymes are made of
Enzymes are made of protein
Define the phrase ‘active site of an enzyme’
The ‘active site’ of an enzyme is the region of the enzyme which is a specific shape to be complementary to the enzymes specific substrate. This shape means that the enzyme and its specific substrate will fit perfectly together during the reaction
Define the phrase ‘ Enzyme-substrate complex’
As a product of ‘ active site of an enzyme’ as soon as the reaction has taken place the substrate will be replaced by product and the complex breaks up
Explain the meaning of the term ‘ complementary’ in terms of enzyme and substrate
Complementary is a term that refers to the corresponding shapes of the enzymes active site and its specific substate that allow them to fit together. The active site and the substrate fit together like pieces of a jigsaw puzzle
- DONOT use the term matching
Explain the term specificity in terms of enzymes and substrate
Each enzyme is a specific to a particular shape. This mean that the active site of one enzyme only corresponds to the shape of one particular substrate. E.G. Catalase can only work on hydrogen peroxide, amylase only works on starch ect
Identify two types of enzyme reactions
Enzyme reactions can be categorised as either synthesis or degradation reactions. Synthesis reactions build up small substrates into larger products. Degradation reactions break down large substrates into smaller products
Give examples of degradation and synthesis enzyme reactions, identifying the substrate, enzyme and product(s)
Explain the term ‘Optimum’ as applied to a range of conditions on which enzymes operate
Optimum is a term used to refer to the conditions in which an enzyme will be most active i.e. conditions where the enzyme will work at its fastest rate. The two main conditions that affect enzyme activity are temperature and PH
Describe the effect temperature and PH on the rate of an enzyme-controlled reaction if its at its optimum
If the temperature and PH are optimum for an enzyme-controlled reaction it will be working at its fastest rate.
Describe the effect temperature and PH have on the rate of an enzyme-controlled reaction if its not at its optimum
If the temperature or PH are decreased below optimum or increased above optimum then this will reduce the enzyme activity and the rate of the reaction will decrease
Explain what happens to an enzyme when its denatured
When an enzyme has been denatured the shape of its active site has been changed. The rate of the reaction controlled by the enzyme will decrease. Enzymes and other proteins can be denatured by changed away from optimum PH and by temperatures above optimum temperature
Explain why a denatured enzyme is no longer functional
When an enzyme has been denatured the shape of the enzymes active site is no longer complementary to its substrate. This means that the enzyme can no longer operate because its active site no longer fits the shape of its specific substrate
