TOPIC B2 ORGANISATION Flashcards
what are organ systems
organisms working together to perform a specific function
what are similar cells organised into
tissues
define the term tissue
-a group of similar cells that work together to carry out a particular function
-it includes more than 1 type of cell
state 3 tissues in mammals
-muscular tissue, contracts to move whatever its attatched to
-glandular tissue, which makes and secretes chemicals like enzymes and hormones
-**epithethal **tissue. which covers some parts of the body e.g inside the gut
define the term organ
a group of different tissues working together to perform cetrain functions
state what the stomach is an organ made up of and why it needs these
The stomach has three roles:
-To mechanically digest food through the churning of food
-To produce the enzyme protease
-To produce hydrochloric acid (stomach acid)
what is an organ system
a group of organs working together to perform a particular function
state 5 organs in the digestive system
-Mouth
-Oesophagus
-Stomach
-Small intestine (duodenum and ileum)
-Large intestine
-Rectum
why does the digestive system need glands
to produce digestive juices
why does the digestive system need the stomach
to digest food
why does the digestive system need the liver
to produce bile
why does the digestive system need small intestine
to absorb soluble food molecules
why does the digestive system need large intestine
to absorb water from undigested food, leaving faeces
state 1way to increase a chemical reaction
by raising temperatures
what is a catalyst
a substance which increases the speed of a reaction, without being changed or used up in the reaction
what are enzymes made up of
-large proteins
-chains of amino acids
why do enzymes only catalyse one reaction
state 2things enzymes need for a reaction
-right temperature (an optimum one)
-right pH (neutral, 7)
state what must of happened for an enzyme to become denatured
-a high temperature increases the rate at first
-if it gets too hot, some bonds holding the enzymes together break
-this changes the enzymes active site so the subsrate will not fit anymore
what are enzymes used in digestion produced and released into
-produced by cells
-released into the gut to mix with food
The lock and key model
- enzymes and substrates move about randomly in solution
- when an enzyme and its complementary substrate randomly collide, with the substrate fitting into the active site of the enzyme, an enzyme substrate complex form
- product form from subsrate are released from the active site. The enzyme’s unchanged and will go on
The effect of temperature on enzyme activity
-enzymes work fastest at optimum temperature
-heating to high temps will start to break the bonds that hold enzymes together, it will start to distort and lose its shape, reducing effectiveness of substrates
-eventually the enzyme is denatured
The effect of pH on enzyme denaturation
-optimum is 7
-if pH is too high/low the bonds that hold the amino acid chain are destroyed
-changing the shape of the active site, so substrate can no longer fit, reducing rates of activity
what molecules need to be broken down by digestive enzymes
-starch, amino acids
-proteins, glycerol
-fats, fatty acids
smaller soluble molecules that pass easily through the walls
Carbohydrases
-break down carbohydrates to simple sugars
-amylase is a carbohydrase which breaks starch into maltose, which is broken down into glucose by the enzyme maltase
Proteases
-a group of ezymes that break down proteins into amino acids in the stomach and small intestine
-protein digestion takes place in the stomach and small intestine
-proteases are made in the stomach (pepsin), pancreas and small intestine
Lipases
-break down lipids (fats) to glycerol and fatty acids
-lipase enzymes are produced in the pancreas
Bile production and storation
MADE- liver
STORED- gall bladder
function of bile
an alkaline which neutralises hydrochloric acid from the stomach
-also emulsifies fat to form small droplets, increasing surface areas
State how alkaline conditions allow lipase to break down
-due to larger surface areas and alkaline conditions they chemically break down fat (lipids) into glycerol and fatty acids faster
-rate of fat breakdown by lipase increases
state the function of liver
where biles produced
state the function of gall bladder
where biles stored before its released into the small intestine
state the function of large intestine
where excess waters absorbed from food
state the function of stomach
-pummels food with muscular walls
-produces protease enzymes
-produces hydrochlonic acid to
1. kill bacteria
2. right pH for protein enzyme to work
state the function of pancreas
-produces protease, amylase and lipase enzymes
state the function of small intestine
-produces protease and lipase
state where gas exchange happens
-in the lungs as they contain millions of little air sacs called alveoli
-theyre surrounded by a network of blood capillaries
how are lungs adapted for gaseous exchange
large surface area= allow FASTER diffusion
thin walls= ensure diffusion distances are SHORT
good blood supply= to maintain a high conc gradient so diffusion occurs FASTER
good ventIliation= with air so diffusion gradients are maintained
Trachea
-a windpipe that connects the mouth and nose to the lungs
learn where its found
Bronchi
-large tubes branching off the trachea, with 1 bronchus for each lung
Alveoli
-tiny moist air sacs, where gas exchange takes place
state how to calculate breathing rate
breaths per minute= number of breathes divided by number of minutes
what is the natural resting heart rate cintrolled by
a group of cells located in the right atrium that act as a pacemaker
function of right ventricle
to pump blood to the lungs where gas exchange takes place
function of left ventricle
to pump blood around the rest of the body
function of aorta
main blood vessel that carries oxygenated blood from the heart to the rest of the body.
vena cava function
a vein that carries deoxygenated blood from the body to the heart.
pulmonary artery
carries deoxygenated blood from the right ventricle of the heart to the lungs for gas exchange.
pulmonary vein
carries oxygenated blood from the lungs to the left atrium of the heart.
what is the circulatory system made up of
-heart
-blood vessels
-blood
state the difference between the double circulatory system and the circulatory system
-double is just the 2circuits joined together
-humans have double
state what you would find in the 1st doulbe circulatory system
-a right ventricle that pumps deoxygenated blood to the lungs to take in oxygen
-blood then returns to the heart
state what you would find in the 2nd circulatory system
-a left ventricle that pumps oxygenated blood around all the other organs of the body
-blood gives up its oxygen at the body celld and deoxygenated blood returns to the heart and to the lungs again
state the role of the heart
-an organ that pumps blood around the body in a double circulatory system
role of valves
to prevent the backflow of blood
step 1 of the 4 chamber process of the heart pumping blood around
1) blood flows into the 2atria from the vena cava and the pulmonary vein
step 2 of the 4 chamber process of the heart pumping blood around
atria contracts, pushing the blood into the ventricles
step 3 of the 4 chamber process of the heart pumping blood around
ventricles contract, forcing the blood into the ventricles and aorta and out the heart
step 4 of the 4 chamber process of the heart pumping blood around
blood flows to the organs through arteries and returns through veins
step 5 of the 4 chamber process of the heart pumping blood around
atria fills again and whole cycle restarts
why is an artifical pacemaker often used
-to control heartbeat if the natural pacemaker cells dont work properly
or if the patient has an irregular heartbeat
state the 3 types of blood vessel
-arteries, carry blood AWAY from the heat
-capillaries, involved with the exchange of materials
-veins, carry blood TO the heart
how are the arteries adapted for its function
-walls are strong and elastic
-contain thick layers of muscle to make them strong
how are capillaries adapted
-thin wall only one cell thick which increases the rate of diffusion
-very small lumen
-permeable wall so substances diffuse in
-theyre tiny
how are the veins adapted
-blood is at a low pressure so walls dont need to be as thick as artieres
-bigger lumen than arteries to help blood flow
-valves to keep blood flow in the right direction
formula for calculating blood flow
-rate of blood flow= volume of blood divided by number of mintues
state the role of blood
-a tissue consisting of plasma, in which red blood cells, white blood cells and platelets are suspended
function of red blood cells
-to carry oxygen from lungs to all the cells in the body
-a biconcave shape to give them a large surface area to volume ratio
-contain haemoglobin
white blood cells
-a blood cell a part of the immune system, and defends the body against disease
State how white blood cells defend against diseases
-Phagocytes engulf and digest pathogens, which destorys them
-Lymphocytes produce antibodies that enhance phagocyte activity
-Some lymphocytes produce antibodys called antitoxins which bind to toxic substances produced by pathogens, which neutralises them
How are white blood cells adapted
-phagocytes have a lobed nucleus and are autonomous, meaning they leave blood and patrol tissues
-lymphocytes have a large nucleus and produce antibodies extremely quickly
Platelets
clot blood
what does haemoglobin become in oxygen
it binds to oxygen to become oxyhaemoglobin
-in body tissues the reverse happens and oxyahemoglobin splits up into haemoglobin and oxygen to release oxygen to the cells
white blood cells defend against
infection
-produce antibodies to fight microorganisms as well as antitoxins
state what helps blood clot
platelets
-small fragments of cells
-no nucleus
-help blood clot at a wound to stop blood pouring out and to stop microorganisms getting in
what is plasma
the liquid thar carries everything in blood
ex
-red +white blood cells
-platelets
-glucose
-carbon dioxide
-urea
