B2b Flashcards
(57 cards)
What are enzymes?
Enzymes are biological catalysts produced by living things
What could increasing the temperature do in some reactions?
Speed up unwanted reactions, not just the useful ones
What’s a catalyst?
A substance that increases the speed of a reaction, without being changed or used up in the reaction
What are proteins made up of?
Chains of amino acids
What does a substance have to do for an enzyme to work?
Fit the special shape
Enzymes need the right what to work?
Temperature and pH
In humans, what’s the temperature that enzymes work at?
Around 37 degrees
What pH do most enzymes work at?
pH 7
What enzyme works at pH 2?
Pepsin, an enzyme in the stomach
What do digestive enzymes do?
Break down big molecules into smaller ones
What does amylase do and where is it found?
Breaks down starch into sugars, found in salivary glands, the pancreas and small intestine
What does protease do and where is it found?
Breaks down proteins to amino acids, found in the stomach, pancreas, small intestine
What does lipase do and where is it found?
Breaks down lipids into glycerol and fatty acids, found in the pancreas and small intestine
What does bile do?
Neutralises tthe stomach acid and emulsifies fats
Give the name of each different place in the digestive system and how it’s catalysed by each enzyme
Salivary glands make amylase
Liver: Bile is produced here, it neutralises stomach acid and emulsifies fats
Stomach: Pummels food with walls, produces pepsin (protease enzymes) and produces HCl
Gall bladder: Where bile is stored
Pancreas: produces protease, amylase and lipase
Small intestine: Produces protease, amylase and lipase also. Digested food is absorbed into the blood here
Large intestine: Where excess water is absorbed from the food
What is respiration?
The process of releasing energy from glucose which goes on in every cell
What’s the equation for aerobic respiration?
Glucose + oxygen → carbon dioxide + water + energy
What is the energy released in respiration used for?
- Build up larger molecules from smaller ones (proteins/amino acids)
- In animals- allows muscles to contract
- In mammals and birds - energy is used to maintain body temperature
- In plants- used to build sugars, nitrates and other nutrients which are built up into proteins
When you exercise what do your muscles need?
More glucose and oxygen to work
What needs to be removed from the muscles during exercise?
Carbon dioxide
How does your body react to exercise to remove CO2 and provide oxygen and glucose?
- Breathing rate increases: meets the demand for extra oxygen
- Heart rate increases: blood pumps quicker to get oxygen and glucose to working muscles
How is glycogen used in exercise?
When muscles use up glucose rapidly, some stored glycogen is converted into glucose to provide energy
What is anaerobic respiration?
The incomplete break down of glucose which produces lactic acid- ‘without oxygen’
What’s the word equation for anaerobic respiration?
Glucose → Energy + lactic acid
