Topic 2 - Organisation Flashcards
What are all organisms made from ?
Cells
What is an organ ?
A group of tissues working together to perform a specific function
What is a tissue ?
A group of similar cells working together to perform a specific function
What is an organ system ?
A group of organs working together o perform a specific function
What are the levels of organisation from smallest to largest ?
Cell, Tissue, Organ, Organ system, Organism
What is the purpose of digestion ?
It breaks down large insoluble molecules into smaller soluble molecules which can be absorbed by the bloodstream.
What is the role of the small intestine ?
It produces enzymes and is where small molecules are absorbed into the blood.
What is the function of the liver ?
It produces bile to neutralise the acidity of the stomach acid.
What is the role of the pancreas ?
It produces enzymes such as insulin
What is an enzyme ?
A biological catalyst which speeds up reactions in the body
What is the lock and key theory ?
All enzymes are specific to their substrate which fit into their active sites.
What is the induced fit model ?
Enzymes can change shape slightly to better fit a substrate.
What is Amylase ?
Amylase breaks down starch into glucose.
What is Protease ?
Protease breaks down proteins into amino acids.
What is Lipase ?
Lipase breaks down lipids into fatty acids and glycerol
What is Carbohydrase ?
Carbohydrase breaks down carbohydrates into simple sugars.
Where is each enzyme produced ?
Amylase - salivary gland, pancreas and small intestine. Protease - stomach, pancreas and small intestine. Lipase - pancreas, small intestine
List 3 control variables for the amylase investigation and explain why they are needed.
Temperature, concentration of starch, concentration of amylase ;
because these will affect the rate of the reaction
Explain what happens to enzyme action at high temperatures
They denature, the heat changes the shape of the active site so they substrate no longer fits and the enzyme no longer works.
What happens to enzymes at the wrong pH ?
They denature, the heat changes the shape of the active site so they substrate no longer fits and the enzyme no longer works.
Explain why amylase would not work in the stomach
Amylase works best at pH 5/6 . The stomach contains acid, so the enzyme would be denatured in the stomach.
What is the reagent and positive result for glucose / sugars ?
Benedicts solution - Colour change blue to brick red
What is the reagent and positive result for starch ?
Iodine - Colour change orange to blue-black
What is the reagent and positive result for protein
Biuret’s solution - Colour change blue to purple
What is the reagent and positive result for lipids ?
Ethanol and water - Colour change colourless to cloudy
Are the enzyme tests qualitative or quantitative ?
They are qualitative since it shows whiter or not a substance is there - not how much of it is present.
What is the function of bile ?
Bile emulsifies fat and neutralises stomach acid
Where is bile stored ?
In the gallbladder
What is emulsification ?
Breaking down into smaller particles
How does bile help lipase to function ?
Emulsification increases surface area for lipase to work on. Neutralilsation makes the optimum pH for lipase to work.
What happens in the alveoli ?
Gas exchange (diffusion of oxygen into the blood, diffusion of carbon dioxide out of the blood into the alveoli)
Describe the pathway of oxygen into the bloodstream
Trachea, bronchus, bronchioles, alveoli, capillary
Why are the alveoli surrounded by capillaries ?
To maintain a concentration gradient, keep oxygenated blood flowing away from the lungs.
What is the double circulatory system ?
Two separate circuits- to lungs and to body. The blood passes through the heart twice.
What are the four chambers in the heart ?
Right atrium Left atrium
Right ventricle Left ventricle
What are the different functions of the right and left side of the heart ?
Right pumps blood to the lungs. Left pumps blood to the body.
Where is the pacemaker located ?
In the wall of the right atrium
What is a pacemaker ?
It controls the heart beat through electrical impulses
What is an artificial pacemaker ?
An electrical device which controls the heart beat
What is the function of the arteries?
To carry oxygenated blood to the tissues
How are arteries adapted to their function ?
It has a narrow lumen and thick muscular walls to maintain high pressure.
What is the function of the veins ?
To carry deoxygenated blood to the heart
How are veins adapted to their function ?
It has valves to prevent back flow of blood at low pressure
What is the function of a capillary ?
To carry blood to and from the body tissues
How are capillaries adapted to their function ?
Walls are one cell thick so there is a short distance for diffusion.
What are the four components of blood ?
Red blood cells . white blood cells, plasma and platelets
What is the function of red blood cells ?
To carry oxygen
What is the function of white blood cells ?
Part of the immune system- destroys pathogens
What is the function of the platelets ?
Forms blood clots (scabs)
What is the function of the plasma ?
To carry dissolved substances and the other components of the blood (Eg. urea)
What organs are affected by cardiovascular disease ?
The heart, lungs and blood vessels
What is the consequence how having faulty heart valves ?
Less blood is able to be pumped around the body, so cells do not get the substances they need
What is the treatment for faulty valves ?
Replacement with biological or mechanical valves
Describe the treatments for heart failure
Heart transplant, or artificial hearts
Explain the positives and negatives of the treatments for heart failure
-Heart transplant can be a long term solution, but donors are sparse, and there is a danger of rejection.
-Artificial hearts are only a short term solution, but can allow hearts to rest as an aid to recovery.
How does the heart muscle tissue get oxygen and glucose?
Through the coronary artery
What causes and consequences of coronary heart disease ?
A build up of fatty layers in the coronary artery - preventing proper blood flow therefore the tissues do not get enough substances
Describe two treatments for CHD
Statins- pills to reduce cholesterol and
Stents- tubes which keep arteries open.
Describe a positive na negative of each treatment against CHD
Statins- cheap, non-invasive, no risk of infections, but need to be used long term.
Stent- Invasive, so risk of infection, but can be a long term solution.
Describe the function of each tissue in a plant
Palisade mesophyll- photosynthesis
Spongy mesophyll- diffusion of gases
Xylem- transport of water and minerals
Phloem- transport of sugars
Guard cells- open and close the stomata
Stomata- allow gas exchange and control water loss
Explain how each function of the plant links to its adaptations
Palisade- contain many chloroplasts,
Spongy- contains air spaces
Xylem- hollow tubes
Phloem- contains cell sap and pores at each end of cell
Guard cells- can change shape
What is meristem tissue ?
Undifferentiated cells in plants ( Stem cells )
Where is the meristem tissue located ?
At the tips of roots and shoots
How are root hair cells adapted to their functions ?
Have long hairs to give a large surface area
Function and adaptation of the xylem
Carry water and mineral around the plant, hollow cells forming tubes
Function and adaptation of the phloem
Carry sugars around the plant. Has sap which ca move between cells via pores at each end.
What is transpiration ?
Evaporation of water and loss through stomata of leaf
What are the 4 factors that affect transpiration ?
1) Temperature
2) Humidity
3) Light intensity
4) Air movement / wind intensity
What is translocation ?
The movement of suagrs around the plant in the phloem.
