Transport Flashcards
why do multicellular organisms need transport systems
-diffusion to all cells would be too slow to meet the organism’s needs, so transport systems are required
role of the xylem
transport water and mineral ions from roots to other parts of the plant
role of phloem
transport sucrose and amino acids from where they are produced or stored to where they are needed
how are root hair cell adapted
-large surface area due to long projection for efficient absorption of water by osmosis and minerals via active transport
steps for root hair cells to take in minerals
-active transport using energy from mitochondria
steps for root hair cells to take up water
-osmosis
-water concentration of cell cytoplasm reduced due to presence of mineral ions
-water moves into the root hair cell by osmosis
route of water through the plant
-osmosis into the root hair cell, through the root cortex and into xylem vessels
-carried up to leaves entering the mesophyll cells by (transpiration?)
what does blood consist of
red blood cells, white blood cells, platelets and plasma
approx breakdown of blood by %
plasma - 55%
45% RBC
<1% WBC and platelets
structure of red blood cell
biconcave discs containing no nucleus to maximise capacity for haemoglobin
structure of white blood cells
-large cells containing large nucleus
platelets structure
-fragments of cells
plasma structure
clear, straw-coloured aqueous solution
what does plasma contain
CO2: from respiring cells to lungs
Digested food and mineral ions: from small intestine to requiring cells around the body
Urea: (liver?)to kidneys
Hormones - from endocrine organs to target tissues
Heat energy: to cooler parts/skin where heat can be lost
how are red blood cells to their function of carrying oxygen to respiring cells
-contains haemoglobin, protein that binds to oxygen to form oxyhaemoglobin
-no nucleus to allow more space for haemoglobin to be packed in
-biconcave disc shape gives large surface area to volume ratio to maximise diffusion of oxygen in and out
types of white blood cells
phagocytes
lymphocytes
structure of phagocyte
-cell membrane
-cytoplasm
-lobed nucleus
white blood cells against infection (5)
1 ingest / engulf / surround / phagocytosis / eq;
2 enzymes;
3 digest / breakdown / eq;
4 lymphocytes;
5 antibodies / antitoxins;
6 specific / eq;
7 antigen:
8 memory / memory cell / eq
- phagocytes (engulf) pathogens
- they secrete digestive (enzymes) to (break down) pathogens
- (lymphocytes) produce (antibodies) which bind to (specific) (antigens) of pathogen
- (memory cells) are left behind in the blood after the infection
describe how a phagocyte defends against pathogens
-(phagocytosis)
-cell surface membrane detect chemicals produced by pathogenic cells
-(engulf/pseudopodia) the pathogenic cell when encountered until the pathogen is inside the phagocyte/phagosome
-release (digestive enzymes/lysosome) to break down pathogen
-(vesicles/phagosome fuse with pathogen)
-(products of digestion expelled) from the vesicle and phagocyte
-non-specific response
how do lymphocytes defend against pathogens
-produce (antibodies)
-(specific) to the (antigens) on the surface of the pathogen
-antibodies (bind to and kill) pathogens
-antibodies also mark pathogens for other white blood cells
-make memory cells
what are vaccinations used for
-induce immunity to infectious diseases
-reduces cases of certain diseases or even eradicates them
what do vaccines contain
-harmless pathogens
how do scientists ensure vaccines contain pathogens that are harmless
- killing the pathogen
- making pathogen unable divide or grow
- using fragments of pathogens instead of whole cells
how can vaccines be administered
-orally
-nasally
-via injection
how do vaccines work
-(weaker/inactive pathogens) are administered to the person
-(antigens) in vaccine can trigger an immune response in the bloodstream
-(lymphocytes) recognise antigens in bloodstream
-activated lymphocytes produce antibodies specific to the antigen
-(memory cells) are produced from the lymphocyte
-memory cells and antibodies remain circulating in the blood stream
-if antigen is encountered again, (antibodies are produced faster), sooner and in larger quantities
platelets
fragments of cells that are involved in blood clotting and forming scabs
process of developing a scab
-platelets release chemicals that cause soluble fibrinogen proteins to convert into insoluble fibrin
-this forms an insoluble mesh across the wound
-red blood cells become trapped, forming a cloth
-the cloth dries and develops into a scab
purpose of blood clotting
-prevent excessive blood loss and protect would from bacteria entering until new skin has formed
where does oxygenated blood from the lungs enter and where does it go
-left side of the heart
-pumped to the rest of the body (called the systemic circuit)
where does deoxygenated blood from the body enter and where is it pumped to
-right side of the heart
-vena cava
-pumped to the lungs (pulmonary circuit)
how does the left ventricle muscle differ from the right ventricle
-left ventricle has a thicker muscle wall than the right ventricle as it has to pump blood at high pressure around the entire body
-right ventricle pumps blood at a lower pressure to the lungs
what separates the two sides of the herat
septum
what do veins and arteries do each
veins carry blood towards the heart
arteries carry blood
what do coronary arteries do
supply the cardiac muscle tissue of the heart with oxygenated blood
-the heart is a muscle and needs a constant supply of oxygen and glucose for aerobic respiration to release energy to contract
pathway of deoxygenated blood through the heart
-flows through the vena cava into the right atrium
-atrium contracts and blood is forced through the tricuspid(atrioventricular) valve into the right ventricle
-ventricle contracts and blood is pushed through the semilunar valve into the pulmonary artery
-blood travels to the lungs and moves through the capillaries path the alveoli where gas exchange takes place
-low pressure blood flow on right side prevents damage to capillaries in the lungs
pathway of oxygenated blood
-returns from lungs via the pulmonary vein to the left atrium
-atrium contracts and forces blood through the bicuspid valve (atrioventricular valve) into the left ventricle
-the ventricle contracts and blood is forced through the semilunar valve and out through the aorta
-thicker muscle walls of the left ventricle produces a high enough pressure for blood to travel around the whole body
what is the pacemaker and what does it do
-it is a group of cells located in the right atrium
-they coordinate the contraction of the heart muscle and regulate the heart rate
-they do this my sending electrical impulses which initiates a contraction in the cardiac muscle
what happens to the heart during exercise
- muscle cells respire faster to increase energy supply
- increased respiration raises the need for oxygen, glucose and waste removal
- increased heart rate to deliver oxygen and glucose more frequently
- increased volume of blood pumped to supply larger amounts of oxygen and glucose
what happens to your heart after excercise
heart rate remains high as oxygen is required in the muscles to break down the lactic acid from anaerobic respiration
what is coronary heart disease
-fatty material (cholesterol builds up inside the coronary arteries, partially blocking it
-flow of blood through the arteries is reduced
-less oxygen and glucose do cardiac muscle cells
-can result in angina (severe chest pains)
-in full blockage cells in the heart cannot respire aerobically
-heart attack
sources of cholesterol
-dietary cholesterol from animal products
-cholesterol synthesised by the liver
risk factors of coronary heart disease
- obesity
-extra weight strains heart
-increased weight can leads to type 2 diabetes, damages (narrows) blood vessels - high blood pressure
-increases the force of the blood against artery walls, damages blood vessels - high cholesterol
-speeds up build up of fatty plaque leading to blockages - smoking
-chemicals in smoke cause increase in plaque build up and increase in blood pressure
-carbon monoxide also reduces oxygen carrying capacity of red blood cells
types of blood vessels
- arteries
- veins
- capillaries
what blood vessels branch off arteries and what branches off after that
arteries -> arterioles -> capillaries -> venules -> veins
features of arteries
-carry blood at high blood pressure
-carries oxygenated blood
-has thick muscular walls containing elastic fibres to withstand high pressure of blood and maintains blood pressure as it recoils after the blood passes through
-narrow lumen to maintain high pressure
-blood flows through at a fast speed
features of veins
-carries blood at low pressure towards the heart
-deoxygenated blood (other than pulmonary vein)
-thin walls
-large lumen reduces resistance so blood flows at low pressure
-contains valves to prevent backflow of blood as it is at a low pressure
-blood flows through at a slow speed
features of capillaries
-carry blood at low pressure within tissues
-carry both oxygenated and deoxygenated blood
-have one cell thick wall, for short diffusion distance
-‘leaky walls’ to allow blood plasma to leak out and form tissue fluid surrounding cells
-slow speed of blood
lymphatic vessels
-collect excess tissue fluid that leaks out of capillaries and delivers t back to the circulatory system
blood vessel towards and away from lungs
towards lungs: pulmonary artery
away: pulmonary vein
blood vessel and away from kidney
towards: renal artery
away: renal vein
blood vessels towards and away from heart
towards: vena cava, pulmonary vein
away: aorta, pulmonary artery
blood vessels towards and away from liver
towards: hepatic artery
away to heart: hepatic vein
away to gut: hepatic portal vein
blood vessels going towards gut
mesenteric artery
process of removing chemical substances from plants
-plant cells break down molecules into chemical substances no longer required needed
-some substances cannot be converted into another useful compound and must be removed from the plant
-these can be stored in the dying tissue of a plant
-when dying tissue falls off the plant the substances are removed
