biology- B2 organisation

amylase digests starch into smaller sugar molecules

hydrochloric acid, helps enzymes to start digestion of protein

turns the food into a fluid increasing the surface area for enzymes to digest

small intestine from liver and pancreas

enzymes continuing digestion of starch and protein, starts digestion of lipids

bile neutralises acid released from stomach, as it is an alkaline solution, speeding up digestion of lipids by lipase

enzymes continuing digestion of protein and lipids

small food molecules broken down by digestion are absorbed into bloodstream through active transport or diffusion

water absorbed into bloodstream

short tube at end of the large intestine, waste material is compressed into a solid form

muscular opening at the end of the rectum, waste material is eliminated from the body

build new carbohydrates, lipids and proteins

some glucose is used in respiration

starch broken down by salivary amylase, produced by salivary glands, into maltose

amylase into maltose

salivary glands, pancreas, small intestine

protease into amino acids

stomach (pepsin), pancreas and small intestine

lipase into glycerol and fatty acids

pancreas and small intestine

emulsifies lipids into smaller droplets, massively increasing surface area of lipid droplets, increasing rate of lipid breakdown by lipase

max frequency of successful collisions between substrate and active site

iodine solution -positive- blue black -negative- orange yellow

benedict's solution, 5 min hot water bath green- small amount yellow- more brick red- lot

doesn't work on non-reducing sugars, e.g. sucrose

buriet solution -positive- purple ring between layers -negative- no change

sudan II, shake positive- red layer forms

1. one drop of iodine solution in spotting tile

2. 3 test tubes, each containing same volume of starch solution, amylase solution, pH 5 solution buffer solution (used to control pH)

3. place 3 test tubes in water bath at 30 degrees C and leave for 10 mins to allow solutions to reach right temp

4. combine 3 solutions, mix using stirring rod

5. immediately return test tube to water bath and start stopwatch

6. after 30s, use stirring rod to transfer one drop of solution to spotting tile

7. iodine turns blue black showing starch is present

8. take sample every 30s until sample remains orange, telling us starch is no longer present and reaction is finished

9. stop stopwatch, record time taken

10. repeat experiment many times, using different pH buffers, e.g. 6,7,8

1. only taking samples every 30s means time recorded for reaction to take place is approximate. instead take samples every 10 seconds

2. looking for when iodine doesn't go blue black, not always obvious as colour change is gradual, hard to see when reaction finished. instead ask several people to look at spotting tile to decide when investigation is finished

very long, 5m in an adult human, very large SA

millions of villi- massive increase SA

covered with microvilli further increase SA

very good blood supply, increase concentration gradient

villi have very thin membrame, short diffusion path

single circulatory system-

deoxygenated blood goes from heart, to gills, where it gains oxygen, and then oxygenated blood passes straight to organs, oxygen diffuses out of blood into body cells, blood returns to heart

problem- blood loses pressure, as it passes through gills before reaching organs, blood can't travel as quickly to organs, meaning not as much oxygen is delivered

double circulatory system-

deoxygenated blood enters right and left atrium of heart through vena cava, atriums contract forcing blood into ventricles, ventricles contract forcing blood out of heart, blood is pumped from heart to lungs through pulmonary artery, blood gains oxygen in lungs, oxygenated blood returns to heart through pulmonary vein, and then leaves the heart through the aorta and is transported to organs, diffusing oxygen from blood to body cells, then the deoxygenated blood re-enters the heart through the vena cava

benefit- blood passes through heart twice, pressure is not lost, travel rapidly to body cells delivering more oxygen

between atrium and ventricles, prevent backflow of blood

thicker muscular wall, left side pumps heart all around body where as right side only pumps to lungs

withstand high pressure from carrying blood, thick muscular walls

blood travels through in surges when heart beats, so elastic fibres stretch

in between surges, elastic fibres recoil, keeping blood moving

allows substances, like glucose and oxygen to diffuse from blood into body cells. carbon dioxide diffuses from body cells to blood.

very thin wall- shorter diffusion path

valves have very thin walls, carry low pressure blood

contain valves which prevent back flow of blood. when blood is flowing in the correct direction valves are open, when blood starts to flow backwards, valves close

plasma, red blood cells, white blood cells, platelets

liquid part of blood

transports:

• soluble digestion products, e.g. glucose, from small intestine to other organs

• carbon dioxide, from body cells to lungs, to be breathed out

• waste product urea from liver to kidneys, to be excreted in urine

transport oxygen from lungs to body cell

adaptations:

• haemoglobin, combines with oxygen to form oxyhaemoglobin, which is released in organs (oxygen released)

• no nucleus, more space to carry haemoglobin

• biconcave shape, greater SA, oxygen diffuses in and out rapidly

part of the immune system

adaptations:

• nucleus containing DNA encoding instructions on how to do job

tiny fragments of cells, helps= blood clotting

it prevents excessive blood loss and the entry of microorganisms

replace lost blood, platelets to help clotting, proteins extracted useful in antibodies

excessive bleeding and brusing

blood transfusions- must have same blood type or it will be rejected from immune system and patient may die

lots of diseases can be transmitted, but in UK, blood is screened for infections so risk is very low

branch from the aorta, and carry oxygen-rich blood to the heart muscle, oxygen is used in respiration, providing energy for contraction

statins- reduce cholesterol in blood, slows down rate that fatty material builds in coronary artery

they are effective, but can cause liver problems

stent- tube used to keep coronary arteries open

blood can flow normally, but won't prevent other areas of coronary arteries flowing, and won't treat underlying causes

they do not fully open, heart has to pump extra hard to get the blood through, causing heart to enlarge

leaky valves causes patient to feel weak and tired0

mechanical valve- last a life time, but increase risk of blood clots, patient take anti-clotting drugs

valve from animal- don't last as long, patients don't have to take drugs

heart of patients with cardiovascular diseases cannot pump enough blood around the body

donated heart and/or lungs

not enough hearts available to treat every patient, patient must take drugs to stop donated heart being rejected by immune system

artificial heart, while waiting for a heart transplant, or allowing damaged heart to rest

increase risk of blood clotting, not a permanent solution as can only be used for relatively short amount of time

trachea

cartilage rings preventing it from collapsing when we inhale

in to blood stream

out of the blood and into the air

very thin walls, meaning diffusion path is very short

very good blood supply, meaning once oxygen diffuses in to blood it is rapidly removed, meaning concentration gradient is very steep

there are millions of tiny alveoli

rate of diffusion, as it brings fresh oxygen into alveoli and takes away carbon dioxide, meaning the concentration gradient is high

contained within a membrane

invade neighbouring tissue and move into bloodstream, forming secondary tumours

radon- radioactive gas, it releases ionising radiation which damages DNA in cells, causing uncontrolled cell division, leading to cancer

communicable lung disease

state of physical and mental well-being

when someone has a weak immune system, e.g. someone with HIV

suffer from infectious diseases

essentially harmless

HPV causing cervical cancer in some people

allergies, e.g athsma or dermatitis

body is infected with pathogen, which immune system fights off, but person is left with allergy

arthritis leading to depression

scientific study of the patterns of disease to determine risk factors

prove cause, but suggests they may be linked

chemical called carcinogens

something that explains how one factor influences another

as large and random as possible

a place may be exposed to more/less radiation, or the people may get more/less exercise

increase of cholesterol levels in blood, increasing rate if fatty acid build up in artery, increasing risk of cardiovascular diseases

increase in blood pressure, increasing risk of cardiovascular diseases

cardiovascular diseases

increases risk of miscarriage, premature birth, low body mass of baby

increases risk of fetal alcohol syndrome, leading to learning difficulties, and other mental and physical problems

addiction and memory loss

blindness or amputation of a limb

form epidermal tissue, protects surface of leaf

transparent so light can pass through it to reach the photosynthetic cells. covered with waxy cuticle, which reduces evaporation from surface of leaf, prevents leaf from drying out

stomata- allows carbon dioxide to enter leaf and oxygen to leave. also controls water vapour that passes out of leaf. controlled by guard cells

palisade cells equipped with lots of chloroplasts which contain chlorophyll to absorb sunlight for photosynthesis

full of air space, allowing carbon dioxide to diffuse through spongy mesophyll to palisade cells. oxygen diffuses the other way

making chlorophyll

movement of sugars and other molecules through phloem tissue

water constantly evaporated from surface of leaves

water loss (vapor) through stomata open for gas exchange

faster when - higher temp

• dry conditions because this is when evaporation works faster

• windy because wind removes any water vapour allowing for quicker evaporation

• high light intensity because this increases rate of photosynthesis, so stomata open allowing carbon dioxide enter, so water vapour can pass out of leaf

guard cells swell and change their shape, causes stomata to open. now co² can diffuse into leaf and be used in photosynthesis