organisation extra flashcards
organisation pyramind
organelle
cell
tissue
organ
organ system
organism
epithelial tissue
covers outside of body as well as internal organs
muscular tissue
contracts to bring about movement
e.g stomach muscular walls to churn food
function o mouth
site of mechanical digestion
food mixed with saliva which contains amylase - digestion of carbohydrates
glandular tissue
contains secretory cells that prodcue and release substances like enzymes and hormones
eg salivary glands producing amylase
pancreas
orgn that makes hormones to control blood sugar and produce enzymes for digestion
whats organ
lots of tissues working together to perform specific function
what is cell
smallest unit of any living thing
whats tissue
lotts of same type of cell working togethether
whast organism
livin thing
whats organ system
system of organs working together to perform specific funtion
peristalsis
food moved down digestive system by process - peristalsis
this is contraction of two seperate muscles in wall of oespoghagus and small int. contractions are wave like and create a squeezing action
once u have chewed ur food, it mixes w/ saliva and forms a bolus
organs in digestive system
oesophagus, stomach, small intestine, large intestine
functions of digesive system
digestion - breakdown of food so it is small n soluble enough to diffuse through walls of small int
absorption - transporting digested food molecules into blood
job stomach
digestion of protein
dangerous microogranginsm killed
adaptatios of stomach
bolus gets soaked in hydrochloric acid which kills bacteria and provides optimum ph for enzymes to work
walls secrete mucus to protect the stomach lining from HCL, enzymes to break down food molecules and acids to provide optimum ph for enzymes to work
muscles of stomach contract to churn food and so food mixes with gastric juices. also performs peristalsis to cause movement of food to small int
function salivary glands
produce saliva which mix with food
saliva has amylase - digests carbohydrates
job oesophagus
carries food and liquid from mouth to stomach
gall bladder job
stores bile
job liver
processes blood coming from small int
produces bile
small int (duodenum) job
digestion of food and abosrption
small int (ileum) job
digestion and absorption
large in (colon) job
abosrpoption water from undigested food , feces made
large int - rectum - job
reeives waste and stores them until it passes out of body
job enzymes in digestion
break down long molecultes which cant be absorbed into useful smaller moleuctles which can be abosrped easily
intestines adaptions
wlls of small int have finger like projections called villi. are very thin, increae surface area of intestine. they have microvilli which further increase SA. increase SA means more places for diffusion
wals one cell thick - short diffusion pathway to blood
netowrk of cappilies ensures good blood supply - concentration gradient maintained - levels of food molecules in small int always higher than in blood so diffusion rapid.
anus job
muscular ring which excretes feces
amylase
starch to simple sugars
made in salivary glands, pancreas, small int
protease
protein into amino acids
made in stomach, pancreas, small int
lipase
lipids to fatty acids and glycerol
made in pancreas, small int
test for starch
iodine solution
turns from orange brown to blue/black if starch present
otherwise no change
gastric juices
thin clear colourless acid fluid secreted by stomahc glands
include HCL, lipase and pepsin
teest for protein
biuret reagent
from blue to purple if protein present
test for sugar
beendict solution - blue colour
turns from blue to orange/red green or yellow if sugar present
test for lipids
ethanol
from colourless to cloudy
what is active site
part of enzye that matches the substrate
what r catalysts
subtances that increase rate of chemical reaction without being used up
why r enzymes speicfic
each enzyme active site suitable for 1 type of subrtate - lok and key mdel
what r enzymes made of
enzymes are biological catalysts made of amino acids, which r joined together in long chain and folded to make 3d structure
what do enzymes do
put molecules together or break em apart
specific enzyme for every reaction
needed to make celll work properly
why enzmes specficf
only substrates w/ complementary shape to acive site can bind to enzyme and react
stage 2 lock key model
substrate w/ complementary shape binds to enzme
fit like key to a lock
stage 1 lock and key model
enzyme looking 4 complementary substrate
sustrates with not complementary shape cant bind to acive site
stage 3 lock key model
enzyme makes reaction happen much more easily and reactant breaks down to products
stage 4 lock key model
products released frm active site
enzyme repeats process
describe what enzymes are and explain how they break down molecules using lock and key mechanism (6 marks)
enzymes r biological catalysts
they increase rate of reaction
each enzyme has different shape and work at different conditions
witihn the shape is an indentation - the active site
only 1 type substrate fits into active site
if hape of enzyme changes, acive site no longer work and enzye has denatured
why do enzyems (and catalysts as a whole) speed up reactions
redue activaiton nrg
if ph or temp too low in a reaction describe reaction
if too low particles dont have much NRG so collisions between particles have less pwr so less chance of reaction occuring
what if temp and ph to high 4 enzyme
enzyme denatures
factors affecting enzymes and rate of reaaction
temp, ph, enzyme concentration, substrate concentration, surface area, pressure
which ph level and temp do amylase, lipase and protease best work at
all work best at normal body temp - 37-38 degrees
amylase works at 7ph - neutral ph - so mouth is neutral ph
protease work best in ph less that 7 (e.g 2) so works best in stomach which is acidic
lipase works in small int where there is alkali ph
Gall stones
gall stones can form blocking gall bladder and bile ducts, due to imbalance of cholesterol in bile
can cuase pain and hinde ridgestion
red blood cells (RBC) job
carry oxygen in blood, taking it from lngs to tissues
RBC adapations
mention all in the 6mrk question
biconcave shape - higher SA, meaning can absorb o2 easier
no nucleus - more space for haemoglobin
have haemoglobin - binds with o2 to form oxyhaemoglobin.
diameter bigger than diameter ofcapillary so it slows down so diffusion of o2 can happen over long period of time
also is flexible so it can enter capillary
job white blood cells
WBCs help defend body from attack
job phagocytes - adaptions
kill harmful microgorganisms
very flexible so they can engulf microgoraganisms
produce digestive enzymes which kill microgorangisms
job lymphoctes - adpations
produce antibodies which kill microgoranisms or cause them to clump together, making it easier for phagocytes to engluf them
also produce antitoxins whch destory toxins made from bacteria
platelets job and adaptions
small fragments of cells
no nlucleus
suspended in lbood plasma
job: help blood clot at wound, form scabs
this is to reduce blood loss and prevent micorganisms entering blood via wond
plasma
straw coloured liquid - mosly water
all blood cells suspended in plasma
since is a liquid, some substances can dissolve in it like co2 or glucose
transports RBCs, WBCs, platelets, waste products (urea, co2), nutriets (glucose)
HOW TO know if a picutre of microorganism was taken by electron mictoscope
black and white img
in 3D
3 ypes blood vessel
artery
vein
capillary
arteries
carry blood at high pressure away from heart
have thick outer wall, thick inner layer of muscle and elastic fibres with narro central lumen to withstand the pressure
veins
veins carry blood at low pressure
have thin outer wall, thin inner layer of muscle and elastic fibres and wide central lumen
this is because they dont need to have blod flowing quickly at high pressure
they have valves to prevent backflow
valves
prevent backflow by closing when blood flows through it
blood pushes past valves which open in only 1 direction
how are blood vessels arragned
in double circulatory system
dbl circulatory system
one system trapnsports blood from heart to lungs and back
other one transports blood from heart to body tissues then back
pulmonary circulation
carries deoxy blood from heart to lungs then back
systemic circulation
carries oxy blood to from heart to tissues then back
adpations capillaries
one cell thick wall - short diffusion distance
diameter smaller than rbc diameter
permeable membrane allows for diffusion
heart
muscular organ pumping blood around body through repeated contractions
why we need blood circulation
for transport of nutrients
to fight disease
to help stabilse body temps
heart walls
thicker on left side - more cells for more mitochondira to provide NRG for contractions
oxygen and glucose needed for respiration 4 nrg comes from coronary arteries
cronary artey and vein
cornary atery takes oxy blood to heart muscle
coronary vein takes deoxy blood from heart muscle to heart
septum
wall splitting left and right chambers of heart
to prevent mixing of blood
thombrosis
when cholestrol sticks to coronary artery it reduces blood flow and can cause blood to clot - thombrosis
reduced flow of blood to heart muscle = chest pain, heart attack or death
statin
common drugs for over 50s.
reduces LDL cholestrol so slows down fatty desposit build up rate
stent
metal mesh placed in artery. tiny balloon used to open it, and blood vessel at same time
baloon removed and stent reamins, blood vessel kept open
bypass surgery
doctors can use parts of vein from other parts of body to replace blocked artery
wrks well for badly blocked arteries, but xpensive and involes risk associated w/ general anaesateitc
avantge stent
straightforward
no need for gen anaestsia
disavantage stent
only used for partially blocked coronary artiery, not badly blockeld ones
avantage bypass surgery
used on artieries w/ more severe blocks
disavantge bypas surgery
expensive
risk with gen anaestetic
portions of vein must be removed form other parts of body
leaky valves
heart valves must withstand lots of pressure, over time they may leak n become stiff and not fully open, making heart less efficient
pacemaker
natural pacemenaker - group of ccells found in riht atrium
serious problems if no work properly
artificila pacemaker
elec device implanted in chest - sends strong elec signals to heart to stimulate it to worrk properly
artificial heart
mechanical device attached to heart, uses air pressue to pump blood around body
avantage artifical pacemaker
stabilises heart beat
can stimulate faster heart rate dring exercise
disavantage artificial pacemaker
risk of blood clotting and infection
need medical checks for restof your life
avantage atifical heart
can use it while waiting for heart transplant
disavantage artifical heart
expensive
where are lungs
in the thorax protected by the ribcage
seperated from digestive organs by diapragm - strong sheet of muscle
how r lungs ventilated
contraction and relaxation of intercostal muscles
adaptations alveoli
Spherical shaped - increased surface area so more places for diffusion
Well ventilated - constant supply of o2 and co2 quickly removed
thin walls - one cell thich walls for short diffusion distance
good blood supply - constant supply of deoxy blood, conc grad. maintained
moist lining - prevents alveolus from cracking and dying, and allows o2 to dissolve in it before diffusing
flower what is it
repordocutive organ of plant
whats stem
contains xyel mand phloem
whats leaf
site of photosynthesis
whats roots
site of absorption of water and mineral ions from soil
plant tissues
epidermal tissue - cover the plant
palisade mesophyll - where photosynthesis takes place
spongy mesophyll - has air spaces for diffusion of gases
xylem - where water is transported from root to leaf
phloem - where nutrients transorted to leaf and other parts of body
meristem tissue - at tips of roots n shoots, have stems cells
adpation leaf
broad and flat to capture lots of sunlight
have xylem and phloem which transport nutrients to the leaf and to other parts of plant (xyelm bringgg h20 for photosynthesis)
have lots of chloroplasts with chlorophyll so it can abosrb light
have stomata on underside so gases can diffuse in and out
palisade cell function and adatpion
job: site of photosynthesis
have lots of choloroplasts so lots of photosynthesis can take palce
block shaped so they can be packed together in leaf
spongy mespophyll function and adaption
job: allows gases to get to palisade mesophyll cell or leave the cell
not packed tightly together - air spaces between them
guard cell and stomata function and adaption
job: stoma - lets gases enter or exit
guard cell - controls openning and closing of stoma
stoma are at the bottom of leaf to limit water loss as it is shaded
waxy cuticle adaption and function
job: prevent water loss from surface of plant
it is waxy and thin
structure of leaf (top to bottom)
way cuticle
upper epidermis
palisade mesophyll cell
bundle sheath cell
vein
xyelm
phloem
spongy mesophyll cells
lower eidermis
guard cell
stoma
axy cuticle
xylem and phloem function
job: xyelm - moves water and mineral ions from roots to leaf
phloem - moves sugars and amino acids around the plant
guard cells and stomata
when light intensity high, guard cells swell and chang eshape, so stomata opens and co2 enters, while o2 and h2o leave.
when hot conditions, guard cells close to reduce water loss. but now plant cant photosynthesise
at night, stomata close so no more photosynthesis
how are ions obtained n transported through plant
ions taken up by diffusion or active transport from area of high conc. to low conc. (vice versa for active transport.). they travel up the plant in the xylem from roots to leaves in 1 direction only
how water obtained n trnasported thru plant
water taken upby osmosis from high conc. to low conc. water travels up in the xylem from roots to leaves and is pulled up thru transpiration stream
how sugar obained n transported
sugar made in leaves in photosynthesis and travel in phloem to other parts of plant 4 use in resiration or to be stored
def transpiration
evaporation of water from the leaves
transpiration stream
when h2o leaves the leaf, h2o in the xylem diffuses into the leaf to replace the water that has been lost. the water molecule at the top of the chain drags the water molecules beneath up as well, while simultaneously, water diffuses into the root hair cell.
this is the transpiration stream.
importance of transpiration
brings water into the leaf which is used for photosynthesis
it also brings dissolved mineral ions for use
it also cools down the plant, which is especially helpful in warm weather
factors affecting transpiration
temp - transpiration increases as temp increase as evaporaion is faster at high temps
dry conditions - transpir. increases as in dry conditions evaporation is faster
windy conditions - rate increases as conc. gradient is made steeper as water molecules outside leaf blown away
light intensity - rate increases because rate of photosynthesis increases so more water lost and gained same tme
phloem adaptation
have sieve tube cells (have no nuclues) which the sugars and amino acids can diffuse through
companion cells proide nrg for active transport needd for this diffusion
flow of sugars and amino acids bidirectional, UP AND DOWN
xylem adaptation
made up of dead cells forming continuous long hollow tube.
strengthened by lignin
flow of water and mineral ions one direction only, UP
translocation
transport of dissolved material within a plant
left lung
left superior lobe
left inferior lobe
bronchial tree
no middle lobe so there is space for the heart
right lung
right superior lobe
right middle lobe
rigt inferior lobe
bronchial tree
breathing in
intercostal muscles contract
ribs moveup and out
diaphragm muscles contract
diaphragm lowers
vol of chest incres
pressure in chest decres
air pressure in lung lower than atmospheric pressure
air rushes in lungs
breathing out
intercostal muscle relax
ribs move down
diaphragm muscle relaes
diaphragm rises
vol of chest decres
pressure in chest incres
air pressure in chest higher than in amosphere
air rushes out of lungs
why do we chew food
chewing is done to break down food into smaller pieces with a larger surface area.
this is so enzymes can work better on them
job of bile
emulsify lipids and form ‘droplets’, which have bigger surface area
also neutralises hydrocloric acid from the stomach
