b3 Flashcards
what are examples of simple carbohydrates and what do they do?
also known as simple sugars- glucose/fructose - fast release of energy
what are examples of complex carbohydrates and what do they do?
also known as starch/cellulose
Long chains of simple sugars joined together
slow release of energy
what are enzymes?
biological catalysts (proteins) that speed up chemical reactions
how do enzymes work?
every enzyme has an active site with a unique shape that fits onto the substance involved in a reaction.
what is the active site?
the part of the enzyme to which the substrate binds
what is a catalyst?
a substance which increases the speed of a reaction without being changed or used up in the reaction
what does protease , amylase and lipase do?
protease breaks down proteins into amino acids
amylase (carbohydrase)breaks down starch into sugar
lipase breaks down fats into fatty acids and glycerol
what happens if the temperature of the enzyme reaction gets too high?what do all enzymes have?
if it gets too hot , some bonds holding the enzyme together break.This changes the shape if the enzyme’s active site , so the substrate won’t fit anymore .The enzyme is said to denature.
All enzymes have an optimum temperature they work best at .
what can also affect enzymes?
the pH -if the pH is too high or too low the enzyme changes shape and the active site no longer has a complimentary fit to the shape of the substrate molecule.
the optimum pH is often neutral pH 7.
what are examples of simple sugars/carbohydrates ?
glucose = made up of one unit of sugar
sucrose =two units of sugar
where can you find amylase?
where can you find protease?
where can you find lipase?
amylase-salivary glands , the pancreas , the small intestine
protease-stomach(pepsin) , the pancreas , the small intestine
lipase-the pancreas , small intestine
what does bile do and where is it found?
bile is produced in the liver and is stored in the gall bladder before its released into the small intestine
bile is alkaline so it neutralises the hydrochloric acid in the stomach making it alkaline
bile also emulsifies fats which gives a much bigger surface area if fat for lipase to work on
stomach
- pummels the food with its muscular walls
- produces protease enzyme pepsin
- produces hydrochloric acid:
- to kill bacteria and give right pH got protease enzyme to work
small intestine
produces protease , amylase and lipase enzymes to complete digestion
-digested food is absorbed out of the digestive system into the blood
large intestine & rectum
large intestine where excess water is absorbed from the food
rectum where the faeces are stored before they are released through the anus
