structured questions Flashcards
a lipase enzyme only acts on one substrate.
explain why it does not act on other substrate
the active site of lipase is only complementary to the shape of fats.
other substrate will not be able to bind to lipase.
hence no reaction occurs
describe the lock and key hypothesis of enzyme action
the enzyme has an active site complementary to the shape of the substrate.
the substrate fits into the active site, forming enzyme-substrate complex
hence reaction occurs
cells in the palisade layer have more chloroplasts than cells in the spongy layer. suggest a reason for this
the palisade layer is nearer to the top surface hence it is exposed to more sunlight for chloroplasts to carry out photosynthesis
name the process by which water is lost through stomata
transpiration
suggest how the guard cells prevent wilting on a hot day
when guard cells become flaccid, stomata closes
suggest a reason why a person may feel tired when the valves fail to work properly
blood flowing to the body contains less oxygen
describe ad explain one difference in the structure of arteries and veins
veins contain valves while arteries do not
because blood flow in veins is under low pressure. vales prevent the back flow of blood to the heart
suggest how a person knows they have a build up of lactic acid
muscles fatigue
cramps
describe the process that occurs in mitochondria
describe aerobic respiration
suggest in terms of the function of a sperm cell, why it has a large no. of mitochondria
so as to release energy during aerobic respiration so that the sperm can swim towards the oviduct
suggest and explain what would happen to the patient´s heart if he did not undergo the by-pass surgery
the cardiac muscles will not receive sufficient blood which transports oxygen and glucose. the muscular walls may die resulting in heart attack
what is the function of the thin film of moisture on the surface of the spongy mesophyll cells
it is to dissolve gases
describe how water is lost from the leaves from the intercellular spaces in the leaves
water vapour diffuses out of the stomata of the leaves
which blood vessels contains blood that has both high oxygen concentration and high blood pressure
aorta
state two health benefits for a smoking who stops smoking
the person would experience improved cardiovascular and immune health which decreases the risk of heart attack, stroke and lung cancer
person would not have a cough as much and have less respiratory problems
suggest what measures might be taken by government to reduce the harmful effects of smoking on health
implement higher taxes
education on the harmful effects of smoking
explain why is there no lactic acid found in the muscles at the first 2 minutes of race/ exercising etc
it is because there was enough energy released from aerobic respiration
explain how smoking leads to the development of bronchitis
it contains irritants that paralyses cilia
mucus builds up, causing difficulties breating
2 health benefits for a smoker who stops smoking
reduce risk of disease (lung cancer & heart disease)
explain why smoker has less oxygen in their blood than the healthy person
the rate of diffusion is reduced due to smaller surface area of damaged alveoli
healthy lung has a larger surface area than damaged lung
why athletes train at a height of 2000m
at high altitude, the body produces more red blood cells, this increases the capacity of oxygen delivered to muscles for respiration
stomata open smaller means that
slower rate of photosynthesis
where is more stomata found
more stomata found on the lower than upper surface
describe how water is lost from the leaves from the intercellular spaces in the leaves
water vapour diffuses out of the stomata
do stomata close or reduce in size?
and how this resulted in change of the shape of stomata
it reduce in size.
guard cells bcm flaccid and change shape to close stomata
describe how wilting occurs and the changes in the leafy shoo when it wilts
rate of water loss is greater than water absorbed, the plant cell become flaccid. stomata closes and plant wilts
explain how water containing red dye reaches the leaves
due to transpiration
water vapour is lost through the stomata of the leaves
creates suction force whichcauses red dye solution to be absorbed into the xylem tissues at the base of the stalk
pathway taken by the water as it moves from the potometer through plant stem and into the surrounding air
water transported up the xylem to the leaves by transpiration pull
in the leaf, water will move out of the xylem and into the surface of mesophyll cells by osmosis, forming a layer of moisture around the surface
water evaporates into the cellular air space and diffuses out through the stomata to the surrounding air
why is it beneficial to place the plant shoot upside down
since stomata are found on the underside of the leaf
allow gases produced to escape more easily
describe what happens to each products after photosynthesis
glucose stored in the leaves. it converts into starch for plant to use
oxygen diffuse out of the leaves from the stomata
it can also be used in respiration in plants
glucose - aerobic respiration
glucose - cellulose found in cell wall ‘
what happens when ventricle fail to work properly. suggest why a person may feel tired
an insufficient oxygen blood is pumped around the body
blood consist of oxygen, thus a person may feel tired
suggest why amount of exercise may have an effect on the chance of a person dying from coronary heart disease
exercise is a form of stress relief
exercise helps to increase metabolic rate and burn excess fat
preventing the deposition of fats
explain why lactic acid is produced in the muscle cells of the athletes
insufficient oxygen
therefore anerobic respiration occurs
why blood sugar level rise and then falls in the hours after breakfast
blood sugar level rise as food (carbs) digest in small intestine and being absorbed into bloodstream
decreased as liver will be stimulated by insulin to convert into glycogen
physical digestion in small intestine
break down large food to small molecules using bile emulsification
chemical digestion
breaks down of large food to smaller soluble molecules by enzymes
physical digestion of mouth
chewing
physical digestion of stomach
churning
does xylem contain nucleus
no
the order of formation of blood clot
platelet
prothrombin
fibrinogen
fibrin
explain why cells in the alimentary canal contain many ribosomes
to synthesis proteins as enzymes are needed in the digestion of food
the function of capillary
allows for diffusion and exchange of substances
explain why lactic acid is produced in the muscle cells of the athlete
insufficient oxygen therefore anaerobic respiration
what happens to the amino acid when it enters to the bloodstream
used by cells to make proteins
excess amino acids undergo deamination forming urea in the liver
what happens to the glucose when it enters to the bloodstream
release energy by respiration
it is converted to glycogen in the liver for storage one
one adaptation of villi and its function
the walls of villi are one cell thick
this reduces diffusion distance allowing for faster absorption of nutrients
is nucleus found in a root hair cell of a plant
yes
name the process by which water vapour is lost through the stomata
transpiration
darker green colour of leaf means…
more chlorophyll
suggest why babies born to mothers who smoke have lower birth weight than average
babies receive less oxygen and it is needed for cell growth
why hepatic portal vein has the highest concentration of amino acids and glucose
as it is absorbs glucose and amino acids and is transported from small intestine to liver
liver has lower concentration cos excess glucose is converted into glycogen and excess amino acids are broken down by deamination
describe what happens in respiring muscle cells during exercise
rate of aerobic respiration increases
energy released during aerobic respiration occurs
lactic acid is produced
