bio

Question 1

what is a conjugated protein

Answer 1

contains non protein group
has prosthetic group - Fe
prosthetic group attached by covalent bonds

Question 2

which non essential hormones are made in the medulla

Answer 2

adrenaline and noradrenaline

Question 3

role of adrenaline

Answer 3

increases heart rate
increases blood glucose conc
converts glycogen in to glucose

Question 4

role of noradrenaline

Answer 4

works with adrenaline
increases heart rate
widens pupils
widens air passage in the lungs
narrowing of blood vessels in non essential organs - increases BP

Question 5

which vital hormones are produced in the adrenal cortex

Answer 5

gluco cort icoids
mineralo cort icoids
androgens

Question 6

role of glucocorticoids

Answer 6

• cortisol regulates metabolism buy controlling how the body converts fats, proteins and cards into energy
• helps regulate BP and cardiovascular function in response to stress
• corticosterone works with cortisol to regulate immune system and suppress inflammatory reactions
• controlled by hypothalamus

Question 7

role of mineralocorticoids

Answer 7

• aldosterone helps control blood pressure by maintaining the balance between salt and water conc in the blood and body fluids
• release mediated by signals triggered by kidney

Question 8

role of androgens

Answer 8

• small amounts of male and female sex hormones
• impact small
• oestrogen, testosterone

Question 9

structure of adrenal gland

Answer 9

outer layer = adrenal cortex
inner layer = medulla

Question 10

steroid hormones

Answer 10

lipid soluble
- can pass through lipid component of cell membrane and bind to steroid hormone receptors
- form hormone receptor complex
- acts as a transcription factor which facilitates or inhibits the transcription of specific gene - oestrogen

Question 11

non steroid hormones

Answer 11

hydrophilic - cannot pass directly through the cell membrane
- they bind to specific receptors on cell surface membrane on the target cell
- triggers cascade reaction mediated by chemicals called second messengers - adrenaline

Question 12

action of adrenaline

Answer 12

• adrenaline is hydrophilic so cannot pass directly through the membrane
• adrenaline attaches to receptor on cell surface membrane
• forms adrenaline receptor complex
• when adrenaline binds to receptor - enzyme adenlylyl cyclase is activated
• adenlylyl cyclase converts ATP to cyclic AMP.
• this activates enzyme protein kinase to convert glycogen into glucose.
• example of a cascade effect as at each stage the number of molecules involved increases

Question 13

role of Kuffer cells

Answer 13

destroy bacteria in the blood travelling through the liver

Question 14

role of sinusoid

Answer 14

sinusoid are small channels surrounded by liver cells - hepatocytes and they carry the blood form the sources to the central vein
the blood fro the hepatic vein and artery and mixed and this increased the o2 content of the blood from the hepatic portal vein - supplying the hepatocytes with enough o2

Question 15

functions of the liver

Answer 15

• bile synthesis - aids fat digestion
• gluconeogenesis
• storage of iron, copper and vitamins
• location of the orthinine cycle
• regulation of glycogen storage
• detoxification

Question 16

deamination

Answer 16

protein metabolism
removal of an amine group
amino acids -> ammonia –> urea

Question 17

ornithine cycle

Answer 17

amino acids –> ornithine + ammonia –> urea + water

Question 18

transamination

Answer 18

conversion of 1 amino acid into another

Question 19

detoxification

Answer 19

breakdown of hydrogen peroxide

hepatocytes contain:
catalase
alcohol dehydrogenase

catalase catalyses
hydrogen peroxide –> o2 + water

alcohol dehydrogenase
ethanol –> ethanal
ethanal –> ethanoate –> fatty acids

Question 20

all or nothing law

Answer 20

if the, stimulus is not strong enough then the
threshold (value) is not reached
which means that
depolarisation (of membrane) is insufficient,
then, it / an action potential, is not, generated - muscle does not contract eg

Question 21

how can you produce timber sustainably using clear felling

Answer 21

• limit size of area that is (felled)
• replanting (of trees that have been felled) 
• minimum distance between (replanted) trees
• allow time for new trees to fully grow (before next felling)
• limiting soil erosion after felling 

Question 22

what is coppicing

Answer 22

• trunk cut close to ground level
• several new shoots grow from cut surface
• protect young shoots from grazers
• process repeated after certain time
• broadleaved species
• rotational coppicing can be repeated indefinitely

Question 23

benefits of coppicing

Answer 23

• new stems grow more rapidly than saplings
• lifespan of tree extended
• provides variety of light levels
• fewer large trees means more light for smaller plants
• provides a variety of habitats
• roots prevent soil erosion
• maintains soil quality
• prevents succession
• large machinery not needed

Question 24

properties of water

Answer 24

• as a solvent
• high heat capacity
• as a coolant
• metabolic importance
• cohesion and adhesion

Question 25

water as a polar molecule

Answer 25

oxygen has a greater affinity for the elections and pulls them closer this results in a weak netgatively charged region on the oxygen atom weak positively charged region on the H+ atom oxygen is slightly more negative hydrogen slightly more positive

Question 26

cohesion and adhesion

Answer 26

the slight negative charge on the 02 atom makes it attract the slight positive + atom of another water molecule and they form a hydrogen bond

Question 27

high specific heat capacity of water

Answer 27

hydrogen bonds require a lot of energy to break them water less dense than ice so it floats

Question 28

chemical defences to herbivores in plants

Answer 28

- Tannins - Alkaloids - Terpenoids

Question 29

Tannins

Answer 29

They have a bitter taste and are toxic to insects as they bind to digestive enzymes in the saliva

Question 30

Alkaloids

Answer 30

large group of bitter tasting compounds found in plants. They act as drugs and affect the metabolism of animals - sometimes poisonous Caffeine - toxic to insects and fungi prevents the germination of seeds Nicotine - toxin produced in the roots of tobacco plants it is stored in vacuoles and released when the leaf is eaten

Question 31

Terpenoids

Answer 31

act as toxins to insects and fungi that might attack the plant Pyrethrin - produced by chrysanthemums - act as insect neurotoxins which interfere with the nervous system act as insect repellents - citronella

Question 32

pheromones

Answer 32

chemical made by an organism which affect the social behaviour of other members of the same species

Question 33

Volatile organic compounds

Answer 33

VOC's act like pheromones and diffuse through the air in and around the plant the planets use these chemical signals to defend themselves They may elect gene switching

Question 34

plants folding in response to touch - mimosa pudica

Answer 34

It contains a toxic alkaloid and the stem has sharp prickles and if the leaves are touched they fold and collapse The leaf falls in a few seconds and recovers as a result of potassium ion movement followed by osmotic water movement