B2 Flashcards
What are the nutrients that are found in food.
Protein: growth and repair
Carbohydrates: energy
Lipids: store of energy
All large molecules are too large too be absorbed into bloodstream so they are digested
What is digestion
Large food molecules are broken down into smaller food molecules by enzyme so they can be absorbed into the bloodstream
What are the part of the digestive system
Mouth: chews food. Containers saliva which has enzyme amylase
Gall bladder: stores excess bile
Oesophagus: connect to stomach. Food passes through it to go into stomach
Liver: makes bile which neutralises acid
Stomach: peristalsis: food churned- bigger surface area for enzymes
Pancreas: where enzymes are made
Small intestine: absorbs nutrients from food into blood through diffusion or active transport
Large intestine: water absorbed it blood
What is an enzyme
They are large protein molecules. They are biological catalysts that speed up the rate of a reaction
Where are protease made? What do they break down?
Made in small intestine, pancreas and stomach. Break down protein into amino acids
Where are amylase made? What do they break down
Made in small intestine, salivary glands and pancreas. Break down carbohydrates into simple sugars
Where are lipase made? Wat do they do
Made in small intestine and pancreas. They bread down fats into a glycerol and 3 fatty acids
What is bile
An alkaline substance made in the liver. Excess bile stored in gall bladder
What does bile do
Neutralise stomach acid and breaks down food into tiny droplets since it is alkaline. Emulsification of lipids- a big lipid molecule is turned into smaller lipid droplets do there is bigger surface area for lipase to break down lipids
What 2 factors effect enzyme activity?
Temperature, PH
How does temperature effect enzyme activity?
The more it increases, the more enzyme activity increases because the enzyme has more kinetic energy and moves faster which results in more collisions with substrate. After optimum temperature reached, enzyme denatures because active sight shape has changes so it no longer fits with the substrate. This results in the enzyme activities decreasing
How does PH effect enzyme activity
If to high or too low enzyme will denature. Enzymes interfere with bonds holding enzymes together
How is small intestine adapted for good digestion
. Good blood supply to maintain concentration gradient
. Capillaries increase surface area
. Moist
. Villi/ micro villi provide large surface area
. Very long small intestine increase time for absorption
. Cells have mitochondria so energy for active transport
What id a single circulatory system
Eg: in fish
. Blood pumped from heart to the gills where it collects oxygen and becomes oxygenated
. Oxygenated blood pass straight form gills to the organs where oxygen diffuses out of blood and into body cells
. Blood returns. The heart
What are problems with single circulatory system
Issue: blood looses lots of pressure when travelling through gills before it reaches organs so blood Tavel slowly so less oxygen is delivered
What is a double circulatory system
Blood travels to the heart twice. Right side of heart pumps deoxygenated blood to the heart. Left side pumps oxygenated blood t rest of the body
What s the benefit of a double circulatory system
Because blood pumped to heart twice, it can deliver oxygen rapidly to cells
The left ventral has a thicker muscle that the ride. Why?
So it can pump oxygenated blood at a higher pressure to the rest of the body
What i the purpose of the coronary artery?
To carry oxygenated blood to the heart muscle cells so the heart can have oxygen to Carry out respiration to have energy so it can pump blood around the body and beat properly
Where are the coronary arteries found?
Branch off the aorta around the heart
What is the job of pacemaker cells
Regulate heart beat by producing electrical impulse
Where are pace maker cells found
In the right atrium
What is the job of an artificial pace maker
Control heartbeat of natural pace maker cells don’t work and if they have an irregular heart beat
Arteries adaptations
Carries blood at heigh pressure, thick muscular wall allow it to withstand high blood pressure, elastic fibres stretch when surge of blood passes through and then recoils between surges which keep the blood moving
Vein adaptations
Carry blood at low pressure, contain valves to stop back flow of blood, thin walls, carry blood from organ to heart with big lumen
Capillary adaptations
Pump blood at high pressure, very thing walls- short infusion pathway, substance diffuses in and out from blood to cells
What 4 components make up blood
Platelets, white blood cells, red blood cells, plasma
What is function of red blood cells
Carries oxygen from lungs to cells in the body. Contains haemoglobin rich carries the oxygen. Has no nucleus. Has a biconcave shape
what is the function of white blood cells
Defend against infections- phagocytosis. Have a nucleus, produce antibodies and anti toxins
What is the function of platelets
Help blood clot at wound. Has no nucleus
what is the function of plasma
Liquid that carries everything in the blood like co2, urea, hormones
What are the pros and cons of donated blood
Pros; many uses in medicine, platelets can be extracted and given to other patients who need them, proteins can be extracted
Cons: may not be same blood type- crucial because of not same patients immune system will reject blood and patient may die of disease transmitted via blood
What is cardiovascular disease
It is a non communicable disease meaning it is not passed on fro person to person and it is not caused by a pathogen. It is when fatty substances build up in the arteries. The arteries become narrower due to the lumen getting smaller . This puts a strain on the blood flowing through to the heart. Less oxygenated blood reaching the heart leads to it not getting enough oxygen so not enough respiration can take place. Thus leads to a lack of energy so the heart can pump efficiently.
What are statins? What do they do? Disadvantages?
These are drugs that reduce the revel of cholesterol in the blood. They do this which slows down the rate of fatty deposits forming reducing the risk of coronary heart disease. Some disadvantages are it is a long term drug which must be taken regularly, effects aren’t instant, negative Side effects, forgetting to take it can lea o liver problems.
What are stents? What do they do? Disadvantages?
These are tubes that are inserted into the arteries to keep them open. This tops them from closing up or becoming block do fatty deposit build up so blood can pass through to heart muscles. Some disadvantages of them are: risk of complications during operation, risk of infection from surgery, blood clot from stent can happen- thrombosis, doesn’t treat underlying conditions.
What is the difference between a faulty heart valve and a leaky heart valve?
Faulty heart valve- valve stiffens so it wont open properly so it wont prevent back flow of blood as well and it can cause heart to stiffen. Also heart has to pump extra hard
Leaky heart valve- blood flow in both directions rather than just forward so blood doesn’t circulate effectively causing patient to feel weak or tired
What are the advantages and disadvantages of mechanical valves
Advantages: last a lifetime so dont need to change as much, lower death rate due to heart related issues, readily available- little wait time
Disadvantages- increase blood clot risk, have to take anti clotting drugs, medicine can cause excessive bleeding, sometime can hear valve opening and closing.
What are the advantages and disadvantages of valves from animals
Advantages: don’t need to take anti clotting drugs, no need for medicine
Disadvantages: don’t last long, more likely to be rejected, may need to be replaced, more likely need immune suppressant drugs, valve may harden, ethical issues
What is the grass exchange surface in the lungs
The alveoli
Describe benign
Non cancerous, can no spread to different parts of the body, is a tumour, found in one area
Describe malignant
Cancerous, is a tumour, cells can break off and go into blood stream. They then travel in blood stream and travel to different parts of the body to form secondary tumours
What are the risk factors of cancer
Substances from environment- radon (radioactive gases increase of lung cancer and ionising radiation damage DNA causing uncontrollable cell division)
Lifestyle- smoking (lung cancer), UV light (skin cancer), alcohol (mouth and throat cancer)
Genetics- breast cancer, prostate cancer, large intestine cancer
What is the function of the waxy cuticle in leaf
Reduce water loss by evaporation. It has a thin layer of oily material. It stops leaf from drying out
What is the function of the epidermis in the leaf
Covers whole plant. Transparent so it allows light through into the plant to the chlorophyll. It protects the surface of the leaf
What is the function of the palisade mesophyll in the leaf
Where most photosynthesis occurs. Lots of chloroplast hear so there is lots of chlorophyll so more photosynthesis can occur
What is the function of the spongy mysophyll in the leaf
Contains big air spaces for gasses to diffuse in and out of cells. Gas exchange occurs here. Co2 diffuses from stomata through spongy mesophyll into the palisade cells.
What is the function of the stomata
Allow co2 to diffuse directly into leaf. Gas exchange control water vapour
What is the function of the xylem tissue?
Transport dissolved mineral ions and magnesium used to make chlorophyll. It transports water up the roots to the steam and leafs for photosynthesis to occur
What is the function of the phloem tissue?
Transport dissolved sugars produced by photosynthesis from leaves to rest of the plant
What is the function of the meristem tissue
Able to differentiate into any specialised plant cell as it has stem cells. This will allow plant to grow. It is found in the shoot tip
What is transpiration
Loss of water from the plant
What are the 4 factors effecting transpiration
Light intensity- more photosynthesis will occur so stomata open to let co2 in and water vapour pass out of the leaf
Temperature- more het leads to more evaporation
Airflow- wind removes water vapour
Humidity- must be dry conditions
