B2 Organisation Flashcards
What makes up the body?
cells –> tissues –> organs –> organ system
What do teeth do?
break down food mechanically. Saliva contains the enzyme Amylase.
What does the stomach do?
contains hydrochloric acid and enzymes that chemically break down food.
What does the liver do?
produced bile which is stored in the gall bladder before going to the small intestine. Bile EMULSIFIES LIPIDS to form droplets, increasing their surface area.
What does the pancreas do?
secretes amylase which breaks down STARCH to GLUCOSE in the small intestine.
What happens in the large intestine?
Water is absorbed into the blood stream.
What happens in the small intestine?
nutrients like glucose are absorbed into the bloodstream by the Villi.
What are enzymes?
Enzymes are biological catalysts that break down molecules.
What do carbohydrases do?
break down carbohydrates into simple sugars
e.g. amylase breaks down starch to glucose.
what does protease do?
breaks down proteins into amino acids.
what do lipases do?
break down lipids into glycerol and fatty acids.
What is the lock and key model?
Enzymes are specific. Substrates bind to a specific active site.
How is the rate of reaction of enzymes altered?
Activity increases with temperature until the enzyme denatures (active site changes shape). pH can also affect rate of reaction.
What is used to identify starch?
Iodine (turns from orange to black).
What is used to identify sugars?
Benedict’s solution (turns blue to orange).
What is used to identify proteins?
Biuret’s (turns blue to purple).
What is used to identify lipids/fats?
Cold Ethanol (turn clear to cloudy).
How does the respiratory system work?
Trachea –> Bronchi –> Bronchioles –> alveoli
How does the heart work?
deoxygenated blood enters through vena cava –> right atrium –> right ventricle –> pulmonary artery (to lungs) –> oxygenated blood comes back into heart through Pulmonary vein –> left atrium –> left ventricle –> aorta (to body)
what do arteries do?
carry blood away from the heat. They have thick walls and thin lumen to withstand high pressures.
What do veins do?
Carry blood back to the heart. Thin walls and wide lumen, valves to prevent backflow.
What are capillaries?
one cell think walls to allow fast diffusion between blood and cells.
What is Coronary Heart Disease?
CHD is when the Coronary artery supplying blood to the heart becomes blocked by fatty material. It can cause heart attacks.
What are stents?
Stents can be used to open up a vessel which is blocked by fatty buildup.
What are statins?
Statins are drugs that help reduce cholesterol and these fatty deposits that can occur.
What does blood carry?
Blood carries red blood cells, white blood cells and platelets (help with clotting blood).
What are communicable diseases?
Diseases which are caused by a pathogen and can be passed on to other people/things. E.g. Flu, cold.
What are non-communicable dieases?
Non-communicable diseases comes from inside the body and cannot be passed on. E.g. cancers, CHD.
What can increase risk of diabetes?
obesity and poor diet.
What can increase risk of heart diseases?
diet, smoking and lack of exercise.
What can increase risk of liver disease?
alcohol.
What can increase risk of lung disease/cancer?
smoking.
what is a carcinogen?
Anything which increases the risk of cancer. E.g. ionising radiation.
What is cancer?
Damaged cells which divide uncontrollably.
What is benign cancer?
Cancer which does not spread throughout the body.
What is malignant cancer?
Cancer which spreads to other parts of the body.
What organs do plants have?
Leaves, xylem, flower, meristem, roots and phloem.
What are xylem cells?
continuous tubes that carry water and dissolved mineral ions upwards. Transpiration -Unidirectional.
What are phloem cells?
Tubes of cells that carry sugars and other nutrients to where they are needed. Translocation - bidirectional.
How can the rate of transpiration be changed?
increase temp, decrease humidity and increasing air movement.
What are nitrate ions?
Nitrate ions are needed for protein synthesis. A deficiency causes stunted growth.
What is Chlorosis?
Magnesium ions. If there is a deficiency you will see yellow leaves, stunted growth due to a lack of chloroplasts.
what makes up the structure of a leaf?
waxy cuticle, upper epidermis, palisade mesophyll, spongy mesophyll, vascular bundle, lower epidermis, stomata, guard cells.
