P1 34 Organisation Flashcards
(47 cards)
1
Q
describe the chain of organisational levels
A
cell -> tissue -> organ -> organ system -> organism
2
Q
function of the pancreas
A
- releases hormones (insulin+ glucagon) to help control blood sugar levels
- releases digestive enzymes (carbohydrase/ protease/ lipase) to aid food digestion
3
Q
function of the gall bladder
A
stores bile
(helps fat digestion, neutralises stomach acid entering small intestine)
4
Q
function of the kidneys
A
- filter waste from the blood
- gets rid of excess water+ salts from the body in the form of urine
5
Q
function of the small intestine
A
- digestion- food is broken down (by digestive enzymes) and absorbed into blood
- releases the digestive enzymes (carbohydrase/ protease/ lipase)
6
Q
adaptation of small intestine
A
walls lined with villi- aid absorption of nutrients by increasing small intestine’s surface area
7
Q
adaptations of villi (3)
A
- microvilli - increase surface area
- walls 1 cell thick - short diffusion distance
- capillaries - good blood supply (for quick nutrient transport in+out) - maintains concentration gradient
8
Q
function of the large intestine
A
- where indigestible food goes
- any water is absorbed+ the remaining food becomes faeces
9
Q
4 functions of the liver
A
- removes toxins from the blood (to make bile)
- makes+releases bile - used to break down lipids into smaller molecules for faster digestion / neutralise stomach acid in small intestine so enzymes can work
- generates body heat
- stores glucose as glycogen when blood sugar concentration is too high
10
Q
function of the oesophagus
A
- moves food to stomach by peristalsis- muscle contractions by rings of cartillage
11
Q
function of the stomach
A
- chemical digestion- hydrochloric acid breaks down food+ harmful microbes
- physical digestion- churns food up
- provides acidic pH for Pepsin to work (break down protein into amino acids)
12
Q
2 functions of bile +how it works
(made/stored)
A
- alkaline so neutralises acidic solution coming from stomach into small intestine- provides optimum pH for enzymes to work
- emulsifies fats to break them down into smaller droplets- increases surface area so lipase can work more efficiently
- released into the small intestine via bile duct
- made in liver
- stored in gall bladder
13
Q
describe carbohydrase enzyme (eg. Amylase)
(made/works in)
A
- digests carbohydrates into simple sugars/glucose
- works in the mouth+ small intestine
- made in salivary glands+ pancreas+ small intestine
- Amylase breaks down starch into maltose sugar
14
Q
describe protease enzyme
(made/works in)
A
- digests protein into amino acids
- works in stomach+ small intestine
- made in stomach+ pancreas+ small intestine
15
Q
describe lipase enzyme
(made/works in)
A
- digests lipids (fats) into fatty acids+ glycerol
- works in small intestine
- made in pancreas+ small intestine
16
Q
describe the test for starch
A
positive result- sample containing iodine solution changes from orange-brown to blue-black
17
Q
describe the test for sugars
A
- add Benedict’s solution to a sample then place test tube in hot water bath
- positive result- sample changes from blue to green-yellow (low sugar level) or orange-red (high level)
18
Q
describe the test for protein
A
positive result- sample containing Biuret solution changes from blue to purple
19
Q
describe the test for lipids
A
positive result- sample containing ethanol+ equal volume of distilled water changes from clear to milky-white
20
Q
describe what enzymes are + the 3 steps of lock and key theory
A
- a protein/chain of amino acids
- biological catalysts- speeds up a reaction without being used up
- can only complete one specific function - complementary shape allows them to fit together
- they break down large insoluble molecules into smaller soluble molecules
- an enzyme attracts substrates to its active site-> catalyses the chemical reaction-> forms smaller molecules
21
Q
describe the effect of temperature on enzymes
A
- increase in temp -> increases rate of reaction (up to a certain amount)
- after around 41 degrees (above body temp) enzymes become denatured- enzyme’s active site can no longer bind with the substrate
- decrease in temp -> reaction is slow as enzymes have little kinetic energy so less frequent collisions w substrates
- optimum temperature (max rate of reaction) around 37 degrees
22
Q
describe the effect of pH on enzymes+ examples
A
- enzymes become less effective or denatured if outside their specific optimum pH
- eg. pepsin (protease produced in stomach)- adapted to work in acidic conditions so stomach produces hydrochloric acid
- eg. bile- neutralises acidic solution coming from stomach so enzymes in small intestine can work in their preferred alkaline environment
23
Q
describe the effect of concentration on enzyme reaction
A
- increase in concentration of substrate -> increased rate of reaction (up to a certain amount) as more substrate molecules available for enzymes to react
- after enzymes’ maximum rate achieved -> any increase in concentration has no effect on rate
24
Q
state steps for effect of pH on enzymes RP
A
- place drops of iodine solution in rows on spotting tile
- label a test tube with the pH to be tested
- place 2cm³ amylase in test tube using a syringe
- add 1cm³ pH buffer solution to test tube using a syringe
- add 2cm³ starch solution to another test tube then add to amylase/buffer solution, start the stopwatch whilst mixing for 10 secs using a glass rod
- use a pipette to place one drop of the mixture on the first drop of iodine (should turn blue-black)
- wait another 10 secs and place another drop of the mixture on the second drop of iodine
- repeat every 10 secs until iodine solution no longer changes colour (remains orange-brown)
- repeat experiment at different pH values
-> the less time the iodine solution takes to remain orange-brown, the quicker the reaction, therefore the better the enzyme works at that pH
25
describe the components of blood
* red blood cells- transport oxygen from lungs to body's cells
* white blood cells- help the body fight infection/ diseases
* platelets- tiny cell fragments that clump together to help blood clot at site of wound+ stop bleeding
* plasma- fluid part of blood that carries other components+ substances throughout body
26
describe adaptations of red blood cells (3)
* contains haemoglobin- binds to oxygen
* no nucleus- more space for haemoglobin
* biconcave disk shape- increases SA:V for faster oxygen diffusion
27
describe types of white blood cells (2)
* lymphocytes- produce antibodies which destroy pathogens
-> also produce antitoxins- proteins which neutralise toxins released by pathogens, so you don't feel ill
* phagocytes- engulf+digest viruses/bacteria (phagocytosis)
28
describe arteries
* carry blood away from the heart
* blood is under high pressure- thick, muscular, elastic walls to stretch
* small lumen
* pulmonary artery carries deoxygenated blood to lungs
* aorta carries oxygenated blood to body
29
describe veins
* carry blood to the heart
* blood is under less pressure- thinner walls
* large lumen
* valves to prevent backflow of blood
* vena cava brings deoxygenated blood back to heart (to go to lungs)
* pulmonary vein brings oxygenated blood to heart (to go to body)
30
describe capillaries
* connect arteries to veins
* very thin walls (1 cell thick)
-> faster rate of diffusion: oxygen+ glucose from blood into cells// CO2 from cells into blood to be disposed
* very narrow lumen- only allow 1 cell to pass through
31
describe coronary heart disease
* build-up of fatty material on lining of coronary arteries narrows lumen-> reduces blood supply to heart
* reduced oxygen supply to heart damages cells-> heart attacks, stroke if oxygen doesn't reach brain
32
state treatments for coronary heart disease (3)
* stents: metal mesh placed in artery+ balloon inflated (later removed) to widen the vessel, no anaesthetic required, can be placed anywhere
* bypass surgery: blocked artery replaced with bits of veins, requires surgery+ anaesthetic, but more effective than stents
* prescribed statins: reduces blood cholesterol to slow down the deposit/build-up of fatty material, but cannot be used to treat affected arteries
33
describe how the heart beats
* a group of cells in the right atrium act as the heart's pacemaker- controls heart rate
* when extra oxygen is needed by cells in tissues (during exercise) pacemaker cells increase heart rate so oxygenated blood is pumped around body quicker
34
state treatments for when someone's heart beats too slowly (5)
ARTIFICIAL PACEMAKER: electronic device sends strong+regular shocks (to the right atrium)
BIOLOGICAL VALVE: replacing faulty valves (stiff/leaking) with human/animal donors
ARTIFICIAL VALVE: replacing faulty valves with mechanical titanium valves
TRANSPLANT:
MECHANICAL HEART: short-term measure when heart completely stops until donor is found
35
pros+cons of artificial pacemakers
/ provides easy breathing+ more energy, improves quality of life
X affected by magnetic fields, prone to infection
36
pros+cons of biological valves
/ doesn't damage red blood cells as they pass through valves
X prone to hardening, only last 10-15yrs, donor needed
37
pros+cons of artificial valves
/ strong, durable, last a lifetime, no donor needed
X damages red blood cells, requires medication to stop blood clotting
38
pros+cons of heart transplants
/ reduces need for medicine, improves health
X high-risk operation, limited supply of donors
39
pros+cons of mechanical hearts
/ readily available, saves a life
X medication needed to stop blood clotting, motor can fail, prone to infection
40
describe adaptations of the lungs (alveoli) for gas exchange (6)
* lungs contain millions of alveoli- larger surface area
* walls are 1 cell thick- short diffusion distance for faster gas exchange
* moist walls- makes diffusion easier
* rich in blood supply (surrounded by capillaries)- faster rate of diffusion
* large diffusion gradient- ventilation maintains steep concentration gradient- faster rate of diffusion into capillaries
* spherical shape- increases surface area
41
describe plant tissues/cells+ their location+ their function (6)
* epidermal tissue: covers the whole plant (top+bottom of leaf), single layer of cells, lower epidermis has stoma to control diffusion
* xylem: roots/stems/leaves, provides support+ transports water/minerals
* phloem: roots/stems/leaves, transports sugars
* spongy mesophyll: leaves, helps gas exchange
* palisade mesophyll: leaves, site of photosynthesis
* meristem tissue: tips of roots+shoots, stem cells - enables plant growth
42
describe plant leaf adaptations (6)
* waxy cuticle - waterproof, minimizes water loss through evaporation
* palisade mesophyll: contain many chloroplasts to carry out photosynthesis, long+thin and closely packed to make space for many cells
* spongy mesophyll: lots of air spaces to allow gases to pass to/from palisade cells/chloroplasts
* guard cells surrounding stomata: open/close to monitor gas loss
* transparent upper epidermis: allow sunlight to pass through to palisade mesophyll
* veins contain xylem+phloem tissues to transport water+ sugar made by photosynthesis
43
describe 4 plant leaf adaptations to reduce transpiration
* waterproof waxy cuticle: covers top of leaf to prevent evaporation
* stomata located on underside of leaf: reduce water loss from evaporation due to sun exposure
* guard cells surrounding stomata: minimise water loss when stomata open for gas exchange
* xylem cells pull up water to leaves to replace water lost by evaporation through open stomata
44
state factors increasing rate of transpiration (4)
* higher wind speed: water vapour is taken away quicker
* higher temp: greater rate of evaporation of water vapour
* lower humidity: less water vapour outside leaf when air is dry so steeper concentration gradient
* higher light intensity: faster rate of photosynthesis, stomata opens more frequently to take in CO2/release O2 so is losing more water
45
describe the 4 steps in the double circulatory system (blood vessels) from vena cava
* vena cava brings deoxygenated blood to the heart (right atrium)
* pulmonary artery takes blood to lungs to gain oxygen (from right ventricle)
* pulmonary vein brings oxygenated blood to the heart (left atrium)
* aorta takes oxygenated blood around the body (from left ventricle)
46
why does a leaf with no light exposure contain glucose but not starch
* starch converted to glucose
* so glucose can be used for respiration (to release energy)
* as no light available to produce glucose from photosynthesis
47
human body cells/components adapted for supplying O2/removing CO2 (5)
* heart made of **muscle cells**: fibres slide past each other for contraction for pumping blood
* **red blood cells**: contain haemoglobin+ no nucleus to carry oxygen
* blood **plasma**: waste CO2 diffuses from cells into blood, plasma transports it to lungs
* **adrenaline**: increases heart rate and breathing rate+depth on demand to take in+supply more oxygen
* **capillaries**: gas exchange (intake+removal)
