Biology Y10 Respiration and the Heart Flashcards
what is hte difference between respiration and breathing
repiration is the chemical reaction, while breathing is a process
word equation for aerobic respiration
glucose + oxygen -> carbon dioxide + water (+ energy)
balanced symbol equation for aerobic respiration
C₆H₁₂O₆ + 6O₂ -> 6CO₂ + 6H₂O (+ energy)
how much energy is released by aerobic respiration
38 ATP
where do the reactants of respiration come from
glucose - digestion of food
oxygen - via lungs and blood
where does carbon dioxide go after being produced
exits via lungs and blood
where does aerobic respiration occur
in cell mitochondria
what is energy for
- build up smal molecules into larger ones
- break down larger molecules into smaller ones
- muscle contraction
- maintain a stable body temperature
- active transport
what happens when aerobically respiring during exercise
- heart rate increases
- arteries supplying active muscles dilate
- breathing rate and depth increases
- muscles convert stored glycogen into glucose
word equation for anaerobic respiration in animals
glucose -> lactic acid (+ energy)
balanced symbol equation for anaerobic respiration in animals
C₆H₁₂O₆ -> 2C₃H₆O₃ (+ energy)
how much energy is released by anaerobic respiration in animals
2 ATP
where does anaerobic respiration take place in animals
in cytoplasm
where does lactic acid go after respiration
accumulates in blood
which respiration is faster and why
anaerobic because less bonds are broken
what does lactic acid cause
muscle fatigue and pain
how do you deal with lactic acid
remove it from the body, or convert it back into glucose, both of which require oxygen/energy from respiration
what happens when plants flood
there is a low oxygen concentration in the soil, so the roots have to respire anaerobically
word equation for anaerobic respiration in plants etc.
glucose -> ethanol + carbon dioxide (+ energy)
balanced symbol equation for anaerobic respiration in plants etc.
C₆H₁₂O₆ -> 2C₂H₆O + 2CO₂ (+ energy)
what is diffusion
the net movement of particles down the concentration gradient from a high concentration to a low concentration
why do organisms rely on diffusion
to move substances across cell membranes
how do you format a ‘describe the graph’ question
as the independent variable increases/decreases, the dependent variable increases/decreases
what happens to diffusion as you increase surface area to volume ratio
it becomes quicker
what is the diffusion like in unicellular organisms and why
quick, because:
* low distance between cell membrane and centre of cell
* substances do not have to travel far
* can enter directly from the environment
what mostly goes into cells by diffusion
oxygen, glucose, amino acids etc.
what mostly goes out of cells by diffusion
carbon dioxide and other waste products
what is the diffusion like in multicellular organisms and why
slow, because:
* low SA:V ratio
* large diistance from cell membrane to centre of cell
* exchange cannot happen fast enough (usually have exchange surfaces and transport systems)
why is diffusion in small intestines good
- villi increase surface area
- layer of epithelial cells - small diffusion distance
- good blood supply - maintain concentration gradient
why is diffusion in lungs good
- alveoli increase surface area
- blood capillaries maintain concentration gradient
- thin - small diffusion distance
why is diffusion in gills good
- lot of smaller filament increase surface area
- good blood supply maintains concentration gradient
why is diffusion in roots good
- highly branched network increases surface area
- surface covered with root hair cells - increases surface area
why is diffusion in leaves good
- small hairs increase surface area
- stomata - decreases diffusion distance
- mesophyll - decreases diffusion distance
equation for fick’s law
rate of diffusion is directly proportional to (surface area * concentration difference) / diffusion distance
what are the functions of the lungs
- enable breathing
- move air in and out (ventilate)
- provide a surface area for gas exchange
what does the nasal cavity do
produces mucus and hairs to trap debris
what do the ribs do
protect lungs
what does the trachea do
connects nasal cavity to lungs, produces mucus to trap debris and lined with cilias which waft mucus up
what do the intercostal muscles do
contract and relax to chage volume of chest cavity
what does the bronchiole do
connects bronchus with alveoli
what does the bronchus do
connects trachea to lungs, lined with goblet cells and cilia
what does the diaphragm do
contracts and relaxes to change the volume of the chest cavity and brings about inhalation and exhalation
what do the alveoli do
site of gas exchange and covered in a dense network of capillaries
how does inhalation work
diaphragm contracts and moves down, which increases the volume in the chest cavity and decreases the pressure of air in the chest cavity, so air moves in and fills lungs
how does exhalation work
diaphragm relaxes and moves up, which decreases the volume in the chest cavity and increases the pressure of air in the chest cavity, so air moves out and empties lungs
what is osmosis
the net movement of water molecules from a region of higher water potential to a region of lower water potential down the water potential gradient across a partially permeable membrane
which intercostal muscles contract for inhalation
external
which intercostal muscles contract for exhalation
internal, but is normally passive
proportion of gases in inspired air
oxygen - 21%
carbon dioxide - 0.04%
nitrogen - 78%
proportion of gases in expired air
oxygen - 16%
carbon dioxide - 4%
nitrogen - 78%
what happens in gas exchange
oxygen goes into blood, carbon dioxide goes out of blood
what are the parts of the heart
left atrium, left ventricle, right atrium, right ventricle
what is the heart
an organ that pumps blood around the body
what are the walls of the heart made from
muscle
what is the average heart rate at rest
70bpm
what do the valves do in the heart
prevent backflow of blood - unidirectional flow
what does the septum do
stop oxygenated blood mixing with deoxygenated blood
what is an artery
a vessel going away from the heart
what is a vein
a vessel going towards the heart
what vessel goes to the lungs
pulmonary artery
what vessel goes to the body
aorta
what vessel comes from the lungs
pulmonary vein
what vessel comes from the body
vena cava
which side of the heart has oxygennated blood
left
what do the coronary arteries do
supply blood and remove waste products
why are there thicker ventricle walls
to pump blood out of the heart
which ventricle wall is thicker and why
left because it has to pump blood around the entire body
what are the features of arteries
thick elastic wall, thick muscle wall, narrow lumen, smooth endothelial cells
what are the features of veins
thin elastic wall, thin muscle wall, wide lumen, have valves
what size are the lumens for capillaries
8 - 10μm - same as red blood cells
what is the purpose of fenestrations in capillaries
to let things through (but not red blood cells)
what is blood
a tissue
what are the roles of blood
- transport useful substances to every cell of the body
- removes harmful waste substances
- transfers heat from active organs to cooler parts of the body
what is the composition of the blood
55% RBCs, 45% Plasma, >1% WBCs and platelets
features of RBCs
- biconcave shape
- thin, large surface area- efficient diffusion
- contain haemoglobin to bind oxygen
- no nucleus - more haemoglobin
features of WBCs
- have a nucleus
- involved in body’s immune response
two types of WBCs
phagocytes - chaange shape to engulf and digest micro-organisms
lymphocytes - produce antibodies or antitoxins to kill micro-organisms
features of platelets
- no nucleus
- small fragments of cells
- help blood to clot at the site of wound - stop blood loss and prevent infection
features of plasma
- mostly water - can dissolve many substances
- acts as a solvent (e.g. for glucose, amino acids etc.)
what is coronary heart disease
when blood vessels (coronary arteries) supplying the heart muscle become narrowed or blocked by a build up of fatty material (cholesterol)
what does buld up of cholesterol increase the risk of
forming blood clots
where does cholesterol come from
mostly the liver and partly from the diet
where is the pacemaker found
right atrium
what does the pacemaker do
controls pumping of the heart by sending out an electrical impulse which spreads to surrounding cells causing them to contract
what happens when heart rate is too slow
not enough oxygen gets round the body
what happens when heart rate is too fast
heart can’t pump effectively
what happens when heart rate is irregular
body doesn’t get a constant supply of oxygen
what happens when valves are not closing properly
puts extra strain on the heart - leaks backwards
what happens when valves are not opening properly
puts extra strain on heart - restricts flow
what could faulty valves cause
- breathlessness
- could be fatal
what are statins and how do they work
drugs used to reduce the levels of cholesterol in the blood, they block an enzyme in the liver needed to make cholesterol
advantages of statins
- inhibits synthesis of cholesterol
- reduces rate cholesterol is deposited
disadvantages of statins
- not immediate
- must be taken regularly
- can cause side effects
how do stents work
1) stent and balloon inserted into clogged artery
2) balloon inflated to expand stent and open artery
3) ballooon deflated and removed, leaving stent
where are stents usually inserted
via the groin
advantages of stents
*effective immediately
* last a long time
disadvantages of stents
- requires surgery with risks
- can cause blood clots
what is an artificial pacemaker and how does it work
small battery operated electrical device which send out regular electrical impulses that stimulate the heart to contract
advantages of mechanical heart valves
- hard wearing - last a long time
disadvantages of mechanical heart valve
- makes a clicking noise
- can cause blood clots - may need to take medication
advantages of biological heart valves
- low risk of blood clots
disadvantages of biological heart valves
- don’t last very long
- risk of rejection (but normally treated to prevent rejection)
what are biological heart valves usually made of
pig or cow tissue
advantages of heart transplant
- chance of a normal life
disadvantages of heart transplant
- must wait for donor heart
advantages of artificial heart
- available ‘immediately’
disadvantages of artificial heart
- not long-term
- needs a lot of machinery - normally stay in hospital 24/7
- risk of blood clots
what happens when anaerobically respiring during exercise
- heart rate increases
- breathing rate increases slightly
