Topic 3 Flashcards
Give examples of probiotic bacteria
Bifidobacteria Lactobacillus (lactic acid bacteria)
What do prebiotics promote
The growth of good bacteria
What kind of bacteria do Probiotics contain
‘Good’
Live bacteria
Name the three different ways that fossils can be formed
Gradual replacement my minerals-teeth, shells, bones don’t decay easily so are replaced by minerals forming rock-like substances
Casts and impressions- organisms buried in soft material, which harder a around the organism as it decays
Preservation- places where no decay happens e.g glaciers too cold, amber no oxygen or moisture, peat Boggs to acidic
A limitation of using fossils for evidence
Records are incomplete as many organisms are to soft and don’t form fossils or are yet to be discovered or form fossils
What can fossils show
How long ago organism existed
What it looked like
How it evolved
Name the limb that shows evidence that all organisms evolved from the same ancestor
Pentadactyl limb
What do you measure the growth of of an organism in
Size -height, lengths, width or circumference
Wet mass
Dry mass
Name the three ways that growth happens
Cell differentiation
Cell elongation
Cell division
Name the difference between growth in animals and growth in plants
Animals stop growing at a certain age and only device cells when repairing after that and lose cell differentiation at young age
Plants continuously grow and continue to differentiate
What are tissues
A group of similar cells that work together to carry out a particular function
What are organs
A group of different tissues that work together to form a particular function
What are organ systems
A group of organs that work together to carry out a particular function
What are the role of read blood cells and the shape
Carry oxygen from the lungs to all cells in the body
In the lungs haemoglobin combines with oxygen through diffusion to form oxyhemoglobin
Reverse happens in body cells
No nucleus so more room for hemoglobin
Biconcave show for more surface area
Lack of iron in diet blood can’t carry enough O2= anaemia
What is the role of white blood cells
Defend against disease
Produce antibodies to kill unwanted organisms
Change shape to gobble up microorganism
Low white blood cell count= higher risk of infection
Too high= cause infection or lukemia
Function of platelets
Help blood clots
Stop blood poring out and microorganisms getting in
Function of plasma
Liquid that carries everything In the blood
Carries CO2
Pale yellow liquid
Carries waste products from liver to kidneys
Carries hormones
What are the three different types of blood vessels
Arteries
Capillaries
Veins
What are arteries
Carry blood away from heart
Carry blood under high pressure
Artery walls are strong and elastic
And thick compared to lumen in the middle
Strong enough to carry blood at high pressure
What is the function of capillaries
Small
One cell thick- increases rate of diffusion by decreasing the distance to travel
Permeable walls
Supply food and oxygen and take away CO2
What is the function of veins
Take blood back to the heart
Don’t have thick walls because of low pressure
Bigger lumen to help the blood flow under low pressure
Calves to keep blood flowing in right direction
What is digestion
The breakdown of food into soluble products
Name two ways that the breakdown of food accrues
Mechanically by chewing
Digestive enzymes e.g carbohysrases, proteases, lipases
What do carbohydrases break down and what do they break down into
Starch into sugar e.g amylase
What is the role of proteases
To break down proteins into amino acids e.g pepsin
What does lipase break down and what into
Turns fats into fatty acids and glycerol
What accrues in the mouth to break down food
Saliva and physical real down of teeth chewing
What happens in the oesophagus
Tube that takes food from mouth to stomach
Lined with muscles that contract helping the ball of food move down by peristalsis
Name six parts of the digestive system
Liver Gall bladder Stomach Pancreas Small intestine Larger intestine
What does the liver of in the digestive system
Produces bile
What does the bile in the liver do
Emulsifiers fats and neutralises stomach acids
What is the role of the gall bladder
Bile is stored the released into the small intestine
What does the small intestine do
Produce amylase, lipase and protease to complete digestion
When food is absorbed out of digestive system and into body
What is the role of the stomach
Pummels food with muscular walls
Produces protease enzyme pepsin
Produces HCL that kills bacteria
Gives right PH for enzyme to work at PH2
What is the role of the pancreas
Produces protease, amylase and lipase and releases them into the small intestine
What is the role of the large intestine
Excess water is absorbed from food
What kinds of foods can probiotics be found in
Yogurt, soya milk and dietary supplements
Already there or added by manufacture
What do probiotics do
Help keep digestive system healthy and immune system strong
What are prebiotics in
Carbohydrates we can’t digest e.g oligosaccharides
Naturally in leeks, onions and oats
Why take prebiotics
Because there are not enough in normal diet so supplements containing prebiotics must be taken for good food supply for ‘good’ bacteria already in digestive system
Help promote growth in gut
What do prebiotics help to do
Improve health of digestive system and strengthen immune system
Where do stanol esters accure and what do they contain
In plants
Chemicals that lower cholesterol and reduce risk of heart disease
Why and how are stanols chemically produces
Because stanols are only of small quantities in plants
Commercially produced using bacteria to convert sterols (fats found in plants) into stanols
What are stanols and and who would take them
Yogurts/ dairy products and spreads
People worried about blood cholesterol levels these options
When looking for evidence what steps are taken
Scientific study published in reputable journal
Written by qualified person
Sample of people tested/asked large enough for reliable results
Other studies finding similar results
In the experiment of investigating the effect of different concentrations of digestive enzymes on a substrate e.g amylase concentration on digestion of starch what is used to model the gut and what are the positives and negatives
Pros
Like gut, only let’s small molecules through not bit ones
Cheaper, easier, less gross, than animal gut
Negatives
Not same, human gut=longer and massive surface area
-speed of absorption different
What tests for starch
Iodine
What tests for sugar
Benedicts solution
Name the order of more sugar present for Benedict’s solution
Blue Green Yellow Orange Brick red
What does it show if the Iodine solution is orangey-brown
No starch ever present
Starch molecules to big to pass through busking tubing into water
What does done solution show if changes from blue
Sugar is present in water
Starch broken down into amylase to sugar in Viking tube and smaller molecules small enough to pass through membrane into water
What is peristalsis
Muscle tissue down digestive system
What are the muscles in peristalsis and what are their used
Longitudinal muscles down length of gut= contractions run ahead to keep food in ball
Circular muscles in circles around gut= push food along gut
Job to squeeze food along-action of peristalsis
What is the purpose of bile
HCL makes stomach acidic for enzymes in small intestine to work at
Bile=alkaline=neutralises-making conditions alkaline
Breaks down fats giving bigger surface area for enzyme lipase to work on= digestion quicker
Where is villi found
Inside small intestine
Covered in millions of villi
Name three features of villi that improves absorbing diffested food in blood stream efficient
Big surface area-absorbed quicker into blood
Single layer of surface cells-digested food diffuses quickly over short distance
Good blood supply via capillary network to assist quick absorption of digested food
