Organisation Flashcards
What is differentiation?
process by which cells become specialised for a specific job
What do specialised cells form?
tissues
What do a group of different tissues working together form?
organs
What is a tissue?
a group fo similar cells that work together to carry out a particular function.
Give examples of tissues?
muscular tissues
glandular tissues
epithelial tissues - inside of gut
What is an organ?
group of different tissues that work together to perform a certain function
Give examples of an organ?
stomach
liver
small intestine
What is an organ system?
a group of organs working together to perform a particular function
Give an example of an organ system?
digestive system
What are enzymes?
biological catalysts
What do living things have going on inside them?
different chemical reactions happing all the time
Why do we need enzymes?
reduce the need for high temperatures and they speed up the reaction
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 of?
enzymes are large proteins, proteins made up of chains of amino acids.
the chains fold into unique shapes which enzymes need to do their job
What do chemical reactions usually involve?
things being split apart or joined together
What does every enzyme have?
an active site which a unique shape that fits onto the substance involved in a reaction
Why do enzymes only catalyse for one specific reaction?
for enzyme to work the substrate has to fit into active site, if substrate doesn’t match active site then reaction went be catalysed
Why do enzymes need the right temperature?
at first increasing temp increases reaction, if too hot some bonds holding enzyme together break, changes shape of enzymes active site and substrate won’t fit - enzyme has become denatured
What do all enzymes have?
an optimum temperature they work at
How does the ph effect enzymes?
if too high or too low, ph interferes with bonds holding enzyme together, changes the shape of the active site and dentures enzyme
What is the optimum Ph for most enzymes?
Ph 7
Give examples of big molecules?
starch, protein and fats
What breaks the big molecules into smaller ones?
digestive enzymes
Why do molecules need to be small and soluble?
so that they can pass early through the wall of the digestive system, allowing them to be absorbed into the blood stream
what is amylase an example of?
carbohydrates
What do amylase do?
break down starch
What does amylase make after breaking down the substance?
maltose
Where is amylase made?
salivary glands, pancreas and small intestine
What do carbohydrases convert and into what?
converts carbohydrates into simple sugars
What do proteases convert and into what?
proteins into amino acids
Where are proteases made?
the stomach, pancreas, small intestine
What do lipases convert and into what?
lipids into glycerol and fatty acids
Where are lipases made?
pancreas and small intestine
Where is bile produced?
the liver
Where is bile stored?
gall bladder
Where is bile released?
the small intestine
What makes the stomach too acidic?
hydrochloric acid
What is wrong with the stomach being so acidic?
enzymes in small intestine can’t work properly
What does bile do?
- neutralises the hydrochloric acid and makes the small intestine alkaline so enzymes can work best
- emulsifies fats ( breaks them down into tiny droplets) so they have a bigger surface area of fat for the lipase to work on so digestion is faster
Where are enzymes in the digestive system produced?
glands and gut lining
How do you prepare a basic food test?
- break up piece of food using pester and morter
- add to a beaker and add some distilled water
- stir and dissolve some food
- filter solution with funnel and filter paper and get rid of solid bits of food
What do you use to test for sugars?
Benedicts solution
What are the two types of sugar?
non-reducing and reducing
explain how you can test for reducing sugars?
- transfer 5cm of food sample into test tube
- prepare water bath to 75 degrees
- add Benedicts solution
- place in water bath for 5 mins
- will change from blue to either green, yellow or brick red depending on strength of sugar
What do you use to test for starch?
iodine solution
Explain how to test for starch?
- transfer 5cm cubed of food sample into test tube
- add few drops of iodine solution and gently shake
- change from browny orange to black or blue-black
What do you use to test for proteins?
biuret solution
Explain how to test for proteins?
- transfer 2cm cubed of food into test tube
- add 2cm cubed of buret solution and mix by gently shaking
- from blue to pink or purple
What do you use to test for lipids?
sudan III
Explain the test for lipids?
- transfer 5cm cubed into test tube
- use a pipette to add 3 drops of Sudan III solution to test tube and gently mix
- will operate out into two layers, top layer bright red
Where are the lungs?
In the thorax
Where does the air you breathe through go through?
trachea