B2.5 Proteins - their functions and uses Flashcards
What are proteins made up of?
Long chains of amino acids
How are amino acids structured?
They are folded to produce a specific shape that enable other molecules to fit into the protein
What do proteins act as?
Hormones, antibodies, catalysts and structural components of tissues such as muscles
What do catalysts do?
Increase the rate of chemical reactions
What is the name for biological catalysts?
Enzymes
What are enzymes?
Proteins
Why does every enzyme have a unique shape?
So it can fit onto the substance involved in a reaction
What happens if the enzyme doesn’t fit the substances shape?
It will not catalyse the reaction
The shape of an enzyme is…
Vital for the enzyme’s function
What happens if the temperatures are too high for an enzyme?
It’s shape is destroyed and changed, it becomes denatured
What also affects enzymes?
pH
Different enzymes work best at…
Different pH values
Do all enzymes work inside cells?
No, some enzymes work outside body cells, e.g. the digestive enzymes
What do digestive enzymes catalyse?
The breakdown of large food molecules into smaller molecules
What is the enzyme amylase produced by?
The salivary glands, pancreas and the small intestine
What does amylase catalyse?
The breakdown of starch into sugars in the mouth and the small intestine
What is the enzyme protease produced by?
The stomach, pancreas and the small intestine
What does protease catalyse?
The breakdown of proteins into amino acids in the stomach and the small intestine
What sis the enzyme lipase produced by?
The pancreas and the small intestine
What does lipase catalyse?
The breakdown of lipids (fats and oils) into fatty acids and glycerol in the small intestine
What does the stomach also produce?
Hydrochloric acid
Why does the stomach produce hydrochloric acid?
Because the enzymes work best in acidic conditions
What does the liver produce?
Bile
Where is the bile stored?
In the gall bladder
Where is the bile released into?
The small intestine
What does the bile do?
It neutralises the acid from the stomach. This provide alkaline conditions in the small intestine, in which the enzymes in the small intestine work most effectively. It also emulsifies fats
What enzymes may biological detergents contain?
Protease and lipase
At what temperatures are biological detergents more effective at?
Lower temperatures than other types of detergents
What enzymes are in baby food and why?
Protease, used to ‘pre-digest’ the protein for the baby
What are carbohydrases used for in industry?
Converting starch into sugar starch
What is isomerase used for in industry?
Converting glucose syrup into fructose syrup, which is much sweeter and therefore can be used in smaller quantities in slimming foods
What are enzymes used to bring about in industry?
Reactions at normal temperatures and pressures which would have otherwise require expensive, energy- demanding equipment
What is the purpose of the muscular walls in the stomach?
They churn up the food
What happens at the small intestine?
Food is absorbed out of the digestive system and into the blood
What happens at the large intestine?
Excess water is absorbed from the food
What are digestive enzymes produced by?
Specialised cells in the glands and the lining of the gut
What are some disadvantages for using enzymes in the industry?
They denature at high temperatures and they can be costly to produce
