Enzymes Flashcards
Structure of a protein molecule?
Long chains of amino acids, with different arrangements giving different proteins
Four types of protein?
Structural (muscles and tendons), hormones (insulin), antibodies, catalytic enzymes
Structure of an enzyme?
Folded chain of amino acids, give a specific shape, allowing substrates to fit in, called the active site
What might cause enzymes to denature?
Temperature or pH
Why can’t an enzyme die?
It is a molecule so not living, it can only denature
What makes digestive enzymes different from most normal enzymes? (2)
They work outside of cells; they have an optimum pH of 2
Where are proteases produced and what do they do?
Stomach, pancreas and small intestine - break down protein into amino acids
Describe how fats are digested
Bile emulsifies fats (because they are insoluble in water), giving it larger surface area. Lipids (fats and oils) -> fatty acids and glycerol, catalysed by lipases, made in pancreas and small intestine
What’s the purpose of amylase?
Breaks down starch into glucose (maltose) in the mouth and down the gullet until they reach the stomach, where they are denatured by acidic conditions
Why is the stomach at pH 2?
HCl is produced alongside pepsin, an enzyme with an optimum of pH 2
How and why is semi-digested food from the stomach alkaline?
Bile from the liver is alkaline, which neutralises stomach acid and makes it alkaline, ideal for small intestinal enzymes
Advantages of biological detergents
Break down proteins and fats that causes stains. Work better at lower temperatures, not too high so less energy used. Could be allergenic so put into capsules to prevent it. Enzymes may enter rivers and seas. They do not kill pathogens and nor do low temperatures.
Why are proteases used in baby food?
Pre-digest proteins, making it easier for baby to absorb amino acids needed for growth
How and why is glucose syrup turned into fructose syrup?
Isomerase enzyme used because there is the same amount of energy in both, but fructose is sweeter. Therefore more sweetness for fewer calories
Disadvantages of using enzymes in industry?
Enzymes denatured at high temperatures and with the wrong pH, which are expensive to control. Enzymes are expensive to produce.
