Organisation Mock Flashcards
How do cells specialise?
Through the process of differentiation
What is a tissue?
A group of similar cells that work together to carry out a particular function
What is an organ?
A group of different tissues that work together to perform a certain function
What is an organ system?
A group of organs working together to perform a particular function
Organ systems work together to make _________
Organisms
What are enzymes?
Catalysts produced by living things - biological catalysts
What do enzymes do?
They reduce the need for high temperatures and only speed up useful reactions
Every enzyme has a _____ ____ with a ____ shape that fits onto the substance involved in the reaction
active site
unique
What has to fit into the active site of the enzyme?
The substrate
How many reactions does each enzyme usually catalyse?
One specific reaction
Enzymes need
The right temperature
The right pH
What is meant by an enzyme becoming denatured?
The shape of the active site changes so the substrate no longer fits the enzyme meaning it no longer works
What happens to an enzyme if the temperature increases too much?
Some of the bonds holding the enzyme together breaks, changing the shape of the enzyme’s active site, meaning the substrate no longer fits - denatured
What is meant by the optimum temperature of an enzyme?
The temperature enzymes work best at
What happens if the pH is too high or too low?
The pH interferes with bonds holding the enzyme together, changing the shape of the enzyme’s active site, meaning the substrate no longer fits - denatured
What do digestive enzymes do?
They break down big molecules (starch, proteins and fats) that are too big to pass through the walls of the digestive system, into smaller ones (sugars, amino acids, glycerol and fatty acids)
Carbohydrase converts _______ into _______ ________
Carbohydrates
Simple sugars
What is an example of a carbohydrase and what does it do?
Amylase
Breaks down starch
What is carbohydrase produced by?
The salivary glands
The pancreas
The small intestine
Protease converts _______ into _______
Proteins
Amino acids
What is protease produced by?
The stomach
The pancreas
The small intestine
Lipase converts _______ into _______ and ____ _____
Lipids
Glycerol
Fatty acids
What is lipase produced by?
The pancreas
The small intestine
Where is bile produced and stored?
It’s produced in the liver and stored in the gall-bladder
Why can’t enzymes in the small intestine work properly in the stomach?
Because the hydrochloric acid in the stomach makes the pH too acidic
What does bile’s alkaline(ness) do?
It neutralises the acid and makes the conditions alkaline - enzymes work best in alkaline conditions
How does bile make digestion faster?
It emulsifies fat, breaking the fat into tiny droplets, giving a bigger surface area of fat for the enzyme lipase to work on
What factors affect the rate of reactions?
Temperature pH Enzyme concentration Substrate concentration Surface area Pressure
What is a limiting factor?
Something that prevents a reaction from occurring at optimum rate
What happens in the large intestine?
Where excess water is absorbed from food
What does the small intestine do?
It produces protease, amylase and lipase enzymes
Soluble food is absorbed out of the small intestine into the blood
What does the pancreas do?
It produces protease, amylase and lipase enzymes that is then released into the small intestine
What does the salivary glands do?
It produces amylase enzymes in the saliva and moisturise food
What does the stomach do?
It mixes food and and pummels it with muscular walls
It produces the protease enzyme, pepsin
It produces hydrochloric acid to: kill bacteria and give the right pH for the protease enzyme to work
What does the liver do?
It produces bile and stores carbohydrates
What does the gall-bladder do?
It stores bile before it’s released into the small intestine
Where is excess water is absorbed from the food?
In the large intestine
What do you use to test for sugars (glucose)?
Benedict’s solution
What would happen to the solution when Benedict’s solution is added, if sugar is present?
blue –> green –> yellow –> brick-red
What do you use to test for starch?
Iodine solution
What would happen to the solution when Iodine solution is added, if starch is present?
browny-orange –> bleach or blue/black
What is the Biuret Test used to test for?
To test for proteins
What would happen to the solution when Biuret Reagant is added, if proteins are present?
blue –> pink/purple
What is used to test for lipids?
Sudan III stain solutions
What does Sudan III do to lipids?
It stains them
What would happen to the solution when Sudan III is added, if lipids are present?
The mixture will separate into 2 layers
What part of the lungs does air split into?
From the trachea into the bronchi, into bronchioles, into alveoli
What is the alveoli surrounded by?
Network of blood capillaries
What diffuses between the alveoli and blood?
Oxygen diffuses out of the lungs into the blood
CO2 diffuses out of the blood into the lungs to be breathed out
What diffuses between body cells and the blood?
CO2 diffuses out of the cells into the blood
Oxygen diffuses out of the blood into the cells
What is the circulatory system made of?
The heart, blood vessels and blood
What is pumped out of the right ventricle and to where?
Deoxygenated blood to the lungs
What is pumped out of the left ventricle and to where?
Oxygenated blood to the organs of the body (not lungs)
Why does the heart have valves?
To make sure that blood flows in the right direction, to stop backflow
What type of blood flows in through the vena cava?
Deoxygenated
What type of blood flows in through the pulmonary vein?
Oxygenated
What type of blood flows out through the pulmonary artery?
Deoxygenated
What type of blood flows out through the aorta?
Oxygenated
Where does the blood go to through the pulmonary artery?
The lungs
Where does the blood go from through the aorta?
The rest of the body
What happens when the ventricles contract?
It forces the blood into the pulmonary artery and the aorta, out of the heart