organisation Flashcards
what are cells used to make?
example: cell -> tissue
cell -> tissue -> organ -> organ system -> organism
how to calculate rate of reaction?
rate of reaction = 1000/time
what are enzymes:
- enzymes are catalysts produced by living things.
- a catalyst is a substance which increases the speed of a reaction, without being changed or used up in the reaction
how do enzymes work?
- each enzyme has an active site with a unique shape that fits onto the substance involved in a reaction
- each substrate then fits with the enzyme (Lock and key)
- the reaction causes the substrate to break down quicker
describe carbohydrases (with an example)
Enzymes called carbohydrases convert carbohydrates into simple sugars.
E.g. amylase is used to break down starch
what do enzymes need?
Enzymes need the right temperature and pH level (optimum levels) otherwise they will denature and not work
describe proteases:
Proteases convert proteins into amino acids.
describe lipases:
Lipases break down lipids (fats) to glycerol and fatty acids.
what are the products of digestion used for?
to build new carbohydrates, lipids and proteins. Some glucose is used in respiration.
what are the digestive organs?
- Salivary glands
- Liver
- Gall bladder
- Stomach
- Pancreas
- Large intestine
- Small intestine
- Rectum
What is the role of the mouth?
Begins the digestion of carbohydrates
What is the role of the stomach?
- Begins the digestion of protein; small molecules such as alcohol absorbed
- Pummels the food with its muscular walls
- Produces the protease enzyme (pepsin)
What is the role of the small intestine - Duodenum?
- Continues the digestion of carbohydrate and protein; begins the digestion of lipids
- Absorbs nutrients
What is the role of the small intestine - Ileum?
- Completes the digestion of carbohydrates and proteins into single sugars and amino acids
- absorption of single sugars, amino acids and fatty acids and glycerol
What is the role of the Large intestine?
- Absorption of excess water
- egestion of undigested food
What is the role of the salivary glands?
Produce amylase enzyme in saliva
What is the role of the liver?
- Bile is produced
- Bile neutralizes stomach acid
- Bile emulsifies fats
What is the role of the gall bladder?
Bile is stored before released into the small intestine
What is the role of the pancreas?
Produces protease, amylase and lipase enzymes
Food test: how to test for sugars and what is a positive result?
Use Benedict’s solution - it changes from blue to red/yellow/green depending on how much sugar is present
Food test: how to test for starch and what is a positive result?
Use Iodine solution - changes from orange to black or blue
Food test - how to test for proteins?
Use Biuret solution - changes from blue to purple
Food test - how to test for lipids?
Use Sudan III - a top layer will form and become bright red
What is the lung structure?
Alveoli, Bronchioles, Bronchi, Trachea
What is the features of the alveoli?
1- Thin lining: the lining of the alveoli is very thin so that gases can quickly diffuse through it.
2- Good blood supply: the alveoli have a dense capillary network so that large volumes of gases can be exchanged.
3- Large surface area: human lungs contain about 500 million alveoli - This speeds up diffusion because gases have more area over which to diffuse.
What is on the left side of the heart?
Aorta, pulmonary vein, left atrium, heart valve, left ventricle