2b) Enzymes and Genetics Flashcards
What causes an Enzyme to become denatured (shape changed) ?
Too high temperature
Too high or too low PH
What is an enzyme?
Proteins (chains of amino acids)
Act as biological catalysts
Speed up the rate if the reaction
Without being changed or used up in the reaction
What is optimum temperature and PH for an enzyme?
Best conditions for an enzyme to work
Temp: 37 degrees Celsius
PH: often 7 (neutral), not always
(E.g. pepsin at PH2 in stomach)
Why do enzymes have a specific shape?
To match the specific reaction it will catalyse
Name 3 digestive enzymes and what they do
Break down big molecules into smaller molecules
Amylase converts starch into sugar
Protease converts proteins into amino acids
Lipase converts lipids into glycerol and fatty acids
What are lipids?
Fats and oils
Where is the enzyme amylase made?
Salivary glands
Pancreas
Small intestine
Where is the enzyme protease made?
Stomach (as pepsin)
Pancreas
Small intestine
Where is the enzyme lipase made?
Pancreas
Small intestine
Where is the bile produced and stored?
Produced in liver
Stored in gall bladder
What does bile do?
Neutralises stomach acid by making conditions alkaline Emulsifies fats (breaks fats into tiny droplets)
Why does bile emulsify fats?
Allows fat to be broken into tiny droplets
Allows fats to have a bigger surface area
Easier for lipase enzyme to digest
Faster digestion
What is absorbed in the large intestine?
Excess water from food
What is the function of the stomach in the digestive system?
It pummels the food with its muscular walls
Produced protease enzyme (pepsin)
Produced hydrochloride acid to kill bacteria and give right PH (2 acidic) for protease enzyme to work
What is the function of the rectum in the digestive system?
Where the faeces are stored before they are excreted through the anus
What is the gullet?
Oesophagus
Define respiration
The process of releasing energy from the breakdown of glucose which goes on in every cell
What is the word equation for aerobic respiration?
Glucose + oxygen > carbon dioxide + water (+energy)
What is the energy released by aerobic respiration used for?
Build up larger molecules from smaller ones (amino acids- proteins)
In animals - allow muscles to contract - allows movement
In mammals and birds - maintain body temperature
In plants - build up sugars, nitrates into amino acids and into proteins
Why does blood have to flow at a faster rate when you increase muscle activity?
Requires more energy
More glucose and oxygen needed for respiration
Extra carbon dioxide needs to be removed from the muscle cells
What is glycogen?
Glucose from food stored in mainly in the liver but also in each muscle
When do we use anaerobic respiration?
When your body can’t supply enough oxygen to your muscles
Why is anaerobic respiration not the best way to convert glucose to energy?
Incomplete breakdown of glucose produces lactic acid
Lactic acid builds up in the muscles which is painful
Causes muscle fatigue as muscles get tired and stop contracting efficiently
Doesn’t release as much energy