B2 Flashcards
What are enzymes
Biological catalysts for chemical reactions
Protein molecules
Explain the lock and key theory
The active site will only bind to its specific substrate because they are complementary to eachother.
A chemical reaction then occurs of which molecule are broken down to produce smaller molecules
What is protease and where is it found
Enzyme that breaks down proteins
Stomach, pancreas, small intestine
Explain the digestion of proteins
Proteins are made up of ling chains on amino acids
When digested, protease enzymes break down proteins back into individual amino acids
Amino acids are then absorbed into bloodstream
After absorption they are joined back together in a different order to form human proteins
What is amylase and where is it found
Enzyme that breaks down starch
Found in salivary glands, pancreas, small intestine
what is a single circulatory system
blood passes through the heart once
what is the downside of a single circulatory system
blood looses its pressure and travels slowly - not giving efficient amount of oxygen
what is a double circulatory system in humans
blood passes through the heart twice for every circuit in the body
deoxygenated blood is pumped from the right side of the heart to the lungs and the oxygenated blood is pumped from the left side of the heart to the rest of the body
explain the pattern of blood flow
1.blood flows into the atria through the pulmonary vein and vena cava
2.the atria contract forcing blood into the ventricles
3.ventricles contract forces blood out the heart through the pulmonary artery and aorta
explain the digestion of starch
- starch consists of a chain of glucose molecules
- amylase enzyme breaks down starch into simple sugars
what is lipase and where is it found
Breaks down lipids
Found in pancreas and small intestine
explain the digestion of lipids
- lipid molecule consists of a glycerol molecule attached to 3 molecules of fatty acids
- lipase enzyme breaks down lipid molecule into glycerol and fatty acids
what is bile and where is it found
made in the liver and stored in gallbladder
Alkaline - neutralises HCL in stomach so that the small intestine enzymes can work t their best rate
Speeds up digestion of lipids but are not enzymes - emulsifies fats
explain the digestion of lipids by bile
bile converts large lipid molecules into smaller droplets
This increases the surface area of lipid which increases rate of lipid breakdown by lipase
what is the effect of temperature on enzymes
- As temperature increases, the rate of reaction increases as molecules have more energy + collisions
- The rate increases until it reaches the optimum temperature- where the enzyme activity is the fastest
- As the temperature increases past the optimum, the enzyme activity rapidly decreases to zero and so the enzyme denatures
what is the effect of pH on enzymes
- A pH too low or too high can lead to the enzyme being denatured
- An enzyme has a specific optimum pH and must stay that pH in order to work at its best rate
- Different enzymes have different optimum pHs
what are coronary arteries
- branch off the aorta and surround the heart
- provide oxygen to muscle cells of heart
- oxygen is used in respiration for contraction energy
what are pacemakers
resting heart rate controlled by a group of cells in the right atrium
Cells send electrical impulses which cause muscle contraction
Artificial pacemakers corrects any irregularities in the heart rate
what are the arteries and its structures
- carry blood away from the heart
- has thick, strong muscular walls to withstand high pressured blood
- have elastic fibres to allow them to stretch and recoil through blood surges passing through
- small lumen
What are the capillaries and its structure
- involved in the exchange of materials at the tissues
- very small and have tiny lumen
- carry blood very close to every cell to exchange substances
- Thin walls giving short diffusion path and increasing rate of diffusion
- Permeable walls
- supply food and oxygen to cells and take away waste eg. Co2
What are veins and their structure
- Carry blood back to the heart
- thin walls as the blood flows at low pressure and thick walls aren’t required
- valves to prevent back flow
- bugger lumen for better blood flow
how do you calculate the rate of blood flow
Rate of blood flow = volume of blood / no. minutes
what is the blood made out of
plasma
platelets
white blood cells
red blood cells
describe the plasma and its functions
- pale straw liquid which carries and transports material
- rbc/wbc and platelets
- soluble digestion products which are absorbed by small intestine
- carbon dioxide
- urea
- hormones
- proteins
- antibodies and antitoxins