Topic 2 - Organisation Flashcards
Catalyst definition
A substance which increases the speed of a reaction without being changed or used up in the reaction
What are enzymes made up of
All large proteins - chains of amino acids
These chains are folded into unique shapes
Why enzymes have specific shapes?
Enzymes have an active site with a unique shape that fits substrate in reaction
Substrate has to match enzymes active site for reaction to be catalysed
Enzymes need right pH and temperature
Increasing temperature may increase rate of reaction initially but too high - enzyme denatures - loses shape
Same for pH
Amylase
Carbohydrase
Catalyses breakdown of starch to maltose
Made in: Salivary glands - pancreas - small intestine
Detection of Starch
Use iodine
Starch present - browny/orange to blue/black
Method for investing pH on enzyme activity
Put drop of iodine in every well in spotting tile
Heat water to 35°C and keep constant
Use syringe to add 1cm3 of amylase and 1cm3 of buffer with a pH
Put tube in beaker and wait 5mins
Add 5cm3 of starch
Record how long takes for starch breakdown by taking drop into spotting tile every 30seconds
Repeat with different pH’s
Proteases
Breaks down proteins into amino acids
Made in: stomach - pancreas - small intestine
Pepsin
Protease
Made in stomach
Works best at pH 2
Lipases
Converts lipids to Glycerol and Fatty acids
Made in: pancreas - small intestine
Bile
Produced in liver
Stored in gall bladder
Released into small intestine
Hydrochloric acid in stomach to low pH (acidic) for enzymes in small intestine
Bile is alkaline so neutralises acid to make conditions alkaline - optimum for enzymes in small intestine
Emulsifies fats - breaks into smaller pieces
Digestive system
Mouth - Salivary glands Oesophagus Stomach Liver Gall Bladder Pancreas Small intestine Large intestine Rectum
Salivary glands
Produce amylase
Stomach
Pummels food with muscular walls
Produces pepsin
Produces hydrochloric acid - kill bacteria - pepsin optimum pH 2
Liver
Bile produced
Bile - neutralises acid - emulsifies fats
Gall bladder
Where bile stored before released into small intestine
Pancreas
Produces protease - amylase - lipase
Releases to small intestine
Small intestine
Produces protease, amylase, lipase
Digested food absorbed into bloodstream
Large intestine
Where excess water absorbed from food
Benedicts test
Test for sugars
Do test in heated water bath
If sugar blue to green - yellow - brick red : depending on mass of sugar
Iodine test
Test for starch
Browny orange to black or blue/black
Biuret test
Test for proteins
Blue to pink/purple
Sudan III
Test for lipids
If lipids present mixture separate into 2 layers top layer - bright red
No lipids - no separate layer
Parts of lungs
Trachea Bronchus Bronchioles Alveoli Ribs Intercostal muscles Diaphragm
What happens at the alveoli
Blood passing alveoli has come from rest of body - lots of CO2 little oxygen
Oxygen diffuses out of alveoli into blood
Carbon dioxide diffuses out of blood into alveoli
Double circulatory system
Humans have a double circulatory system as two circuits
One pumps deoxygenated blood
One pumps oxygenated blood