enzymes Flashcards
What is the role of enzymes in metabolic reactions?
Enzymes act as biological catalysts, meaning they speed up chemical reactions in the body without being used up. They are crucial for digestion, respiration, and other metabolic reactions.
How does temperature affect enzyme function?
Enzymes work best at an optimum temperature.
If the temperature is too low, reactions slow down.
If it’s too high, enzymes denature, meaning their active site changes shape and they stop working.
2.12 - How can enzyme activity be investigated in relation to temperature?
Practical: You can test how temperature affects enzyme activity by using amylase (which breaks down starch into sugar) and measuring how fast starch disappears at different temperatures.
2.13 - How does pH affect enzyme function?
Enzymes also have an optimum pH.
If the pH is too high or too low, the enzyme’s shape changes, affecting its ability to bind with substrates.
2.14B - How can enzyme activity be investigated in relation to pH?
Practical: You can investigate the effect of pH on enzymes by using hydrogen peroxide and catalase (an enzyme that breaks it down into water and oxygen) and measuring the reaction rate at different pH levels.
What are the main parts of the human digestive system?
(there are 7)
Mouth
Oesophagus
Stomach
Small intestine
Large intestine
Rectum
Pancreas
mouth
Mouth – Chews food and mixes it with saliva.
oesophagus
Oesophagus – Carries food to the stomach.
pancreas
Pancreas – Produces digestive enzymes.
stomach
Stomach – Uses acid and enzymes to break down food.
small intestine
Small intestine – Digests food & absorbs nutrients.
large intestine
Large intestine – Absorbs water & forms waste.
rectum
Rectum – Stores waste before excretion
Amylase & Maltase
Amylase & Maltase → break down starch into glucose.
2.28 - How is food moved through the gut?
Food moves through the digestive system by peristalsis, which is wave-like muscle contractions that push food in the right direction.
Proteases (like Pepsin & Trypsin)
→ break down proteins into amino acids
Lipases
→ break down fats (lipids) into fatty acids and glycerol.
- Where is bile produced and stored?
Bile is a yellow-green liquid made by the liver and stored in the gall bladder.
2.31 - What is the role of bile?
Bile has two main functions:
Neutralizing stomach acid so enzymes in the small intestine work properly.
Emulsifying fats (breaking them into tiny droplets) to help lipase digest them faster.
2.32 - How is the small intestine adapted for absorption?
The small intestine absorbs nutrients using villi, which are tiny finger-like structures that:
Increase surface area for absorption.
Contain blood capillaries to transport nutrients.
Have thin walls for faster diffusion.
