Organisation Flashcards
Paper 1 - B2
What is the role of the small intestine in the digestive system?
To digest food using enzymes and for small food molecules to be absorbed into the blood
What is the main nutrient group digested in the stomach?
Proteins
What is the purpose of hydrochloric acid in the stomach?
To create acidic conditions for protease enzymes to work
What is the role of the pancreas in digestion?
To produce enzymes
What are enzymes?
Protein molecules that act as biological catalysts/speed up reactions
Name the theory for how enzymes work
‘lock and key’ theory
Name two places in the body where the amylase enzyme is produced
salivary glands and pancreas
Where in the body is the protease enzyme
produced?
In the stomach
Where in the body is the lipase enzyme produced?
Small intestine
Which molecule is broken down by amylase? What are the products?
Starch into simple sugars
Which molecule is broken down by lipase? What are the products?
Lipids (fats) into glycerol and fatty acids
Which molecule is broken down by protease? What are the products?
Proteins into amino acids
What are the products of digestion used for?
Making new molecules (and glucose for respiration)
Which organ produces bile and which organ stores it?
Produced in the liver, stored in the gall bladder
What effect does bile have on stomach acid?
It neutralises it because it is alkaline
What is the role of bile in fat digestion?
It emulsifies fat to form small droplets which increase the surface area so the lipase enzyme can work at a faster rate
Name the test for sugars in food and state the colour change for a positive test
Benedict’s solution; blue to brick-red
Name the test for starch in food and state the colour change for a positive test
Iodine solution; brown to blue-black
Name the test for protein in food and state the colour change for a positive test
Biuret solution; pale blue to lilac
What chemical can be used to test for fats in food? What will happen in the test if fats are present?
Ethanol; solution turns cloudy
Name the part of an enzyme which is affected by high temperatures and extremes of pH
Active site
What are enzymes made of?
Protein molecule/chain of amino acids
Name two factors that affect the rate of an enzyme reaction
Temperature and pH
What happens to enzymes at very high temperatures and how does this affect how they work?
They denature, meaning that the shape of the active site changes and the reacting molecule no longer fits
What is meant by a double circulatory system?
The left side of the heart pumps blood around the body and the right side pumps blood to the lungs (so blood goes through heart twice for each complete circulation)
Where does the right ventricle of the heart pump blood to?
The lungs
Where does the left ventricle pump blood to?
Around the body
Why is the wall of the left ventricle thicker than the wall of the right ventricle?
The left ventricle pumps blood all around the body, so the muscle is larger
Name the blood vessel that carries blood from the heart to the rest of the body
Aorta
Name the blood vessel that carries blood from the heart to the lungs
pulmonary artery
Name the blood vessel that carries blood from the lungs to the heart
pulmonary vein
Name the blood vessel that carries blood back to the heart from the body
Vena cava