Topic J -Transport in cells and animals Flashcards
definition of diffusion
net movement of particles from high concentration to a lower concentration down a concentration gradient till reaches equilibrium
example of diffusion
gasses and liquids O2 and CO2 diffuse in and out of blood
definition of osmosis
movement of water from an area of high water potential to low water potential down a gradient across a semi permeable membrane
example of osmosis
water enters into root hair cells by osmosis
definition of active transport
net movement of particles from low to high against concentration gradient across semi permeable membrane.
Requires energy
example of active transport
mineral ions are actively transported into root hair cells
what factors effect the rate of movement of substances in and out of cells
surface area to volume ratio
distance
temperature
concentration gradient
why can simple unicellular organisms rely on diffusion for movement of substances in out of cells
all the life processes in a unicellular organism take place in that one cell
why do multicellular organisms need transport systems
Multicellular organisms need organ systems to carry out functions such as:
1. Communication between cells, eg the nervous system and circulatory system
- Supplying the cells with nutrients, eg the digestive system
- Controlling exchanges with the environment, eg the respiratory system and excretory system
how is the heart structured
has 4 chambers, right atrium, right ventricle, left atrium and left ventricle
how does adrenaline effect heart rate
increase heart rate
how does exercise effect heart rate and why
- body’s cells need more glucose and oxygen during exercise, and the blood supplies this
- muscles need more energy = respire more - heart rate increases as activity increases in = blood flow faster=more oxygen into cells + co2 removed
- detected as a faster pulse rate. .
what factors increase the rate of coronary heart disease
smoking
high blood pressure
high levels of salt in the diet
high levels of saturated fat in the diet
describe structure of arteries
thick muscual wall + narrow lumen
contain no valves
blood pressure high due to thin lumen + muscular walls
function of arteries
carries oxygenated blood from heart to organs ( movement out)
structure of veins
thin muscular wall + wide lumen
contains valves
blood pressure = low
function of veins
carries deoxygenated blood from organs to heart ( movement in )
structure of capillaries
1 cell thick + no wall
contains no valves
blood pressure low cos tubes let substances out
function of capillaries
transport blood from arteries ( oxygenated ) to tissue to veins ( deoxygenated
what is blood
a tissue
what is blood made up of
red blood cells
white blood cells
platelets
plasma
what is plasma and what does it contains
the liquid part of the blood
contains dissolved nutrients= CO2, minerals, urea, hormones
function of plasma
carries blood cells around the body
distributes heat round the body
structure of red blood cells
small cells ( 8-10 microns )
biconcave shape
no nucleus
contain lots of haemoglobin
function of red blood cells
transport oxygen using haemoglobin
what does immune system use to respond to disease
white blood cells
name two types of white blood cells
phagocytes
lymphocytes
structure of phagocytes
very large cells
lobed nucleus = allows cell to change shape= fit through gaps
function of phagocytes
ingest pathogens by phagocytosis ( cell eating)
structure of lymphocytes
big nucleus
surface area has receptors that act as antibodies
function of lymphocytes
detects pathogens + antigens
creates new antibodies
antibodies attach to antigens = complimentary binding = destroy pathogens (bacteria + viruses )
PAPER 2
what does vaccination result in
manufacture of memory cells =future antibody production to occur faster + sooner
PAPER 2
function of platelets
red blood cells get trapped in fibrin threads= blood clotting= prevents blood loss and + entry of micro-organisms
need to know the structure of the circulation system
look at pg. 41 of CGP
definition of pulmonary
to do with lungs
definition of hepatic
to do with liver
definition of renal
to do with kidneys
what kind or blood do arteries usually carry
oxygenated
what kind of blood do veins usually carry
deoxygenated
which veins and arteries do not follow the rules in terms of what kind of blood they carry
pulmonary artery (deoxygenated) pulmonary vein ( oxygenated)
describe structure of heat and labels
look at pg. 40 of CGP
how does the heart function
- right atrium receives deoxygenated blood from body through the vena cava
- deoxygenated blood moves through right ventricle which pumps it to the lungs via the pulmonary artery
- left atrium receives oxygenated blood from the lungs via the pulmonary vein
- oxygenated blood moves through the left ventricle, which pumps it around the whole body via the aorta
5.
describe the difference between the left and right ventricle of the heart
- left ventricle= thicker wall than right
2. blood in left ventricle = higher than blood pressure in right ventricle
why does the left ventricle of the heart have a thicker wall and a higher blood pressure than the right ventricle
left ventricle has to pump blood around the whole body
right ventricle only pumps blood to the lungs
what do the valves in the heart prevent
backflow of blood
what are the names of the valves found on the right side of the heart
semi- lunar valve
tricuspid valve
what are the names of the valves found on the left side of the heart
semi-lunar valve
bicuspid valve
