Topic 2- Organisation Flashcards
What is a cell?
The basic building blocks of all organisms
What are tissues?
Tissues are a group of cells with a similar structure and function, working together
What are organs?
A collection of tissues working together to perform a specific function
Describe the nature of enzyme molecules and relate their activity to temperature and pH changes.
As with many chemical reactions, the rate of an enzyme-catalysed reaction increases as the temperature increases. However, at high temperatures the rate decreases again because the enzyme becomes denatured and can no longer function.Changes in pH also alter the shape of an enzyme’s active site. Each enzyme work bests at a specific pH value. The optimum pH for an enzyme depends on where it normally works.
What are enzymes?
Biological catalysts,
Enzymes are proteins that help speed up metabolism, or the chemical reactions in our bodies.
equation for rate calculation:
Rate of reaction=
amount of substrate used or product former OVER
time taken
What is metabolism?
The sum of all the reactions in a cell or organism
What types of metabolic reactions do enzymes catalyse?
- Breaking down larger molecules to smaller molecules (carbohydrates to glucose)
- BUILDING smaller molecules into larger molecules
(Glucose to starch) - Changing one molecule to another
(glucose to fructose)
What is the lock and key hypothesis for enzyme function?
Enzymes have active sites on its surface
enzymes have active sites (the lock) which are in specific shapes, the substrate (the key) must fit into the active site for the enzyme to break it down into its products
How does temperature affect enzyme action?
Increasing emperature increases reaction rate, up until a certain point, (37), If the temp goes higher, the active site changes shape and the enzyme becomes denatured and cannot catalyse the reaction. this is same for ph
Where are carbohydrases, proteases and lipases produced in the body?
- carbohydrase- amylase (salivary gland, pancrease), maltase (small intestine)
- proteases-pepsin (stomach), others (pancrease, small intestine)
- lipases- pancrease and small intestine.
What role do carbohydrases play?
amylase breaks down starch into maltose
(Salivary gland, pancrease)
maltase breaks down maltose into glucose
(small inestine)
What role do proteases play in the digestive system?
Break down proteins into amino acids
What role do lipases play in the digestive system?
Break down lipids into fatty acids and glycerol
How are the products of digestion used?
glucose is used as a substrate in respiration.
to build bigger molecules to form carbohydrates and proteins.
Where is bile made and stored in the body?
Bile is made in the liver and stored in the gall bladder
What is the role of bile in the digestive system?
droplets
It is alkaline to neutralise hydrochloric acid from the stomach.
Bile emulsifies lipids to form droplets- this increases the surface area for the lipase enzyme to work on. (increasing the rate)
What is the purpose of the circulatory system?
carries oxygen and other useful substances to bodily tissues and remove waste products.
How does the double circulatory system work?
- One pathway carries blood from the heart to the lungs
- One pathway carries blood from the heart to the tissues
How do you test for carbohydrates, lipids and proteins?
- Benedict’s test for sugars
- iodine test for starch
- Biuret reagent for protein
investigate the effect of pH on the rate of reaction of amylase
enzyme.
To determine the rate of the amylase activity at different pHs. Students should use a continuous sampling technique to determine the time taken to completely
digest a starch solution at a range of pH values. Iodine reagent is to be used to test for starch
every 30 seconds. Temperature must be controlled by use of a water bath or electric heater.
https://www.bbc.co.uk/bitesize/guides/z9jrng8/revision/4
What is the purpose of the double circulatory system?
- one pathway carries blood from the heart to the lungs (where co2 and o2 exchange happens) (right ventricle)
- one pathway carries blood from the heart to the tissues. (left ventricle)
name the blood vessels associated with the heart
- aorta (oxygenated blood from heart to body)
- pulmonary vein (oxygenated blood from lungs to heart)
- vena cava (deoxygenated blood from body to heart)
- pulmonary artery (carries deoxygenated blood from heart to lung)
- coronary arteries
describe pacemakers
the natural resting heart is controlled by a group cells located in the right atrium that act as pacemakers.
artificial pacemakers are used to correct irregularities in the heart rate. A pacemaker signals the heart to beat when the heartbeat is too slow or irregular.