2- organisation Flashcards
what is differentiation
the process by which cells become specialised for a particular job , it occurs during the development of a multicellular organism
what can specialised cells from differentiation form
tissues, which form organs, which form organ systems
large multicellular organisms(e,g squirells) have different systems inside them for exchanging and transporting materials
what are similar cells organised into- give examples
tissues- a group of similar cells that work together to carry out a particular function, it can include more tha one type of cell
in mammals:
1-muscular tissue- contracts to move whatever its attached to
2-glandular tissue- makes and secretes chemicals like enzymes and horomones
3- epithelial tissue-covers some parts of body e.g.the inside of the gut
what are tissues organised into- give examples
organs are a group of different tissues that work together to perform a certain function
e.g.
the stomach is an organ made up of-
muscular tissue which moves the stomach wall the churn up food
glandular tissue which makes digestive juices to digestfood
epithelial tissue- which covers the outside and inside of the stomach
what are organs organised into
give example
an organ system is a group of organs working together to perform a particular function
digestive system (found in humans and other mammals) break down and absorbs food
- glands (pancrease & salivary glands )produce digestive juices
- stomach and small intestine digest food
-liver produces bile
- small intestine absorbs soluble food molecules
-large intestine absorbs water from undigested food leaving faeces
what do organ systems work together to make
organisms
what are enzymes and what are their function
they are all large proteins made up of chains of amino acids. these chains are folded into unique shapes which enzymes need to do their jobs
they are biological catalysts that reduce the need for high temperatures and we only have enzymes to speed up useful chemical reactions in the body. these reactions are carefully controlled to get the right amount of substances.
usually raising temp makes reactions occur more quickly but it would do this to unwanted ones as well- there is a limit to how far you can raise them temp inside a livig creature before its cells get damaged so enzymes are there.
why does the active site of enzymes help them catalyse reactions
chemical reactions involve splitting or joining
every enzyme has an active site with unique shape that fits onto substance in reaction. enzymes only catalyse 1 specific reaction. for the enzyme to work , substrate has to fit into its active site, if substrate doesnt match enzymes active site, then reaction wont be catalysed
explain the lock and key theory
the active site changes shape a little as the substrate binds to it to get a tighter fit- this is induced fit. substrate gas to fit into the active site of the enzyme
why do enzymes need the right temperature
changing temp changes rate of an enzyme catalysed reaction
higher temp increases rate at first but if too hot, some bonds holding enzyme together break, this changes shape of enzyme’s active site so substrate doesnt fit- enzyme has denatured
all enzymes have an optimum temperature that they work best at
why do enzymes need the right ph to work
ph affects enzymes , if it is too high or low , ph interferes with bonds holding the enzyme together, this changes shape of active site and denatures the enzyme
all enzymes have optimum ph they work best at. often the neutral ph7, but not always
e.g. pepsim is an enzyme use to break downproteins in stomach, works best at ph 2 meaning its well suited to the acidic conditions
why do enzymes need the right ph to work
ph affects enzymes , if it is too high or low , ph interferes with bonds holding the enzyme together, this changes shape of active site and denatures the enzyme
all enzymes have optimum ph they work best at. often the neutral ph7, but not always
e.g. pepsim is an enzyme use to break downproteins in stomach, works best at ph 2 meaning its well suited to the acidic conditions
how do you investigae the effect of pH on enzyme activity
enzyme amylase catalyses breakdown of starch and maltose. -if starch is present iodine solution will change from brown orange to blue black.
1- drop of iodine solution in every well of a spotting tile
2- put bunsen burner on heatproof mat, tripod and gauze over bunsen burner. put beaker of water on top of tripod, heat water until 35 degrees(use thermometer)try to keep temp of water constant
3- use syringe to add 1cm3 of amylase solution to 1cm3 of buffer solution with ph of 5 to a boiling tube, use test tube holders -put tube intio the beaker of water and wait 5 mins
4- use different syringe to add 5cm3 of a starch solution to boiling tube
5- mix contents of boiling tube and start stop clock
6- use continuous sampling to record how long it takes for amylase to break down all of starch
use dropping pipette to take fresh sample from boiling tube every 30 seconds and drop it into well, when iodine solution remains brown orange , starch is no longer presen
repeat with buffer solutions of different ph values to see how ph affects time taken for starch to be broken down
control- concentration and volume of amylase for fair test
rate of reaction-what is rate
a measure of how much something changes over time
how do you calculate the rate of reaction
1000/ time
or
if you are measuring how much something changes over time then you do:
amount it has changed by/ time take
digestive enzymes break down big molecules. explain what big molecules are and how digestive enzymes do this
starch, proteins, fats are big molecules
theyre too big to pass through the walls of digestive system. so disgestive enzymes break big molecules
into smaller ones like sugars(glucose and maltose), amino acids, glycerol, fatty acid, =
these are smaller soluble molecules that can pass easily through walls of digestive system allowing them to be absorbed into the bloodstream
what does carbohydrase convert carbohydrates into
where is amylase made
converts it into simple sugars.
amylase is an example of a carbohydrase, it breaks down starch turning starch into maltose and other sugars
amylase is made in the salivary glands
it is made in the pancrease
it is made in the small intestine
what does protease convert proteins into
where is protease made
= amino acids
proteaseis made in the
stomach(pepsin)
pancreas
small intestine
what does lipases convert lipids into
where is lipase made
=glycerol and fatty acids
lipase is made in the pancrease and the small intestine
give ways the body can make good use of the products of digestion
they can be used to make new carbohydrates, proteins and lipids, some of the glucose (a carbohydrate) thats made is used in respiration
how does bile neutralise stomach acid and emulsify fats
bile is produced in the liver. it is stored in the gall bladder before it is released into the small intestine.
the hcl in the stomach makes ph too acidic for enzymes in small intestine to work -
bile is alkaline so it neutralises acid and makes conditions alkaline
enzymes in small intestime work best in alkaline conditions
bile emulsifies fats -breaking it down into tiny droplets so it has a bigger surface area of fat for the enzyme lipase to work on making digestion faster
enzymes in the digestive system are produced by what and where does this happen
its produced by specialised cells in the glands and gut lining.
different enzymes catalyse the breakdown of different food molecules
1)what do the sallivary glands produce
where are the salivary glands
order going from top to the bottom of body
they produce amylase enzyme in saliva
2) where is the gullet
in the oesophagus
3) what does the liver produce, where is it
liver produces bile , bile neutralises stomach acid and emulsifies fats
found to the left of the stomach
4) what does the stomach produce, where is it
stomach pummels the food with its muscular walls. it produces the protease enzyme,pepsin.
it produces hydrochloric acid to kill bacteria and give the right pH for the protease enzyme to work (ph2-acidic)
5) what does the gall bladder do, where is it
gall bladder is in front of liver, it is where bile is stored before its released into the small intestine
6) what does the pancreas do , where is it
pancreas is just below the stomach, it produces protease, amylase, lipase enzymes- releases these into the small intestine
7) what does the small intestine do, where is it
small intesine is surrounded by the large intestine.
it produces protease, amlase, lipase enzymes to complete digestion. this is where digested foods is absorbed out of the digestive system into the blood
8)where is the large intestine, what does it do
large intestine is located around the small intestine,
it is where excess water is absorbed from the food
9)where is the rectum what does it do
connected to the large intestine. it is where faeces (made up mainly of indigestible foods) is stored before it leaves through the anus
food tests - practical
how do you prepare a food sample
1-get a piece of food and break it up using a pestle and mortar
2- transfer the ground up food to a beaker and add some distilled water
3- give mixture a stir with a glass rod to disslove some of the food
4- filter solution using a funnel lined with filter paper to get rid of solid bits of food
food tests - practical
how do you prepare a food sample
1-get a piece of food and break it up using a pestle and mortar
2- transfer the ground up food to a beaker and add some distilled water
3- give mixture a stir with a glass rod to disslove some of the food
4- filter solution using a funnel lined with filter paper to get rid of solid bits of food
how do use the benedicts test to test for sugars
practical
there are 2 types of sugars- reducing and non reducing.
you can test for reducing sugars in foods using benedicts test
1-prepare food sample and transfer 5cm3 of it to test tube
2- prepare water bath so its set to 75 degrees
3-add benedicts solution to test tube (like 1 0 drops) using a pipette
4- place test tube in water bath using test tube holder and leave for 5 mins, make sure test tube is pointing away from you
if food contains reducing sugar, solution will go from normal blue to green/yellow/brick red
depending on how much sugar is in the food
try this with biscuits,cereal,bread
how do you use iodine solution to test for starch
practical
try with pasta,rice, potatoes
1-make food sample and transfer 5cm3 of your sample to a test tube
2- add few drops of iodine solution and gently shake tube to mix contents, if sample has starch, colour of solution will go from browny orange to black/blue black
how do you use biuret test for proteins
practical
try with meat and cheese
1-prepare sample of food,transfer 2cm3 of your sample to test tube
2- add 2cm3 of biuret solution to sample and mix contents of tube by gently shaking it
3-if food sample has protein, solution will change from blue to pink/purple
how to use sudan III test to test for lipids
practical
lipids found in olive oil, margarine,milk-test for lipids using sudan III stain solution
1- prepare sample of food youre testing (dont need to filter) transfer 5cm3 into a test tube
2-use pipette to add 3 drops of sudan III stain solution to test tube and gently shake tube
3- sudan III stain solution stain lipids. if sample has lipids, mixture will separate out into two layers, top layer will be bright red
explain the lungs and the thorax
the lungs are in the thorax
the thorax is the top part of your body
it is separated from the lower part of your body by a diaphragm
lungs are protected by ribcage , surrounded by pleural membrane
air you breathe in goes through trachea, splits into two tubes called bronchi, (each one is bronchus) one going into each lung
the bronchi split into prgressively smaller tubes called bronchioles
bronchioles finally end at small bags called alveoli where gas exchange occurs
