orginisation - Topic 2 Flashcards
What does the digestive system do?
Breaks down carbohydrates, proteins and fats into smaller, soluble molecules so they can be absorbed into the blood.
What does bile do?
-neutralizes acid from the stomach (alkaline)
- emulsifies fats (helps break big blobs of fat by breaking them into smaller pieces which gives them a larger surface area for digestive enzymes such as lipase to work on)
Factors that impact enzyme activity
Temperature and PH
What would happen if enzymes were placed in the wrong conditions?
The active site will change meaning that the enzyme is denatured and can no longer break down the substrate.
What are enzymes?
Biological catalysts that help break down large insoluble molecules into smaller soluble molecules so that they can diffuse into the bloodstream.
What is the lock and key theory?
Enzymes work on specific substrates. The shape of the substrate must be complementary with the shape of the active site in order to form an enzyme- substrate complex.
Where is bile produced and stored?
Produced in the liver and stored in the gallbladder.
Where is amylase (carbohydrase) produced and what does it do?
Produced in the salivary glands, pancreas and small intestines. Acts on starch to produce glucose.
Where is lipase produced and what does it do?
Produced in the pancreas and small intestines. Acts on fats to produce glycerol and fatty acids.
Where is protease produced and what does it do?
Produced in the stomach, pancreas and small intestines. Acts on proteins to produce amino acids.
Factors increasing diffusion
- increase the surface area
- decrease the diffusion distance
- maintain a concentration gradient
What is the test and colour change for reducing sugars?
Benedict’s test
blue- green/yellow/orange/red
What is the test and colour change for non- reducing sugars?
Iodine test
brown/orange - blue/black
What is the test and colour change for protein?
Biuret’s test
Blue- lilac/pink
Name three types of tissue
- muscle tissue
- epithelial tissue
- glandular tissue
What is the function of the mouth?
-mechanically breaks down food
-mixes food with saliva which contains amylase to break down starch
What is the function of the stomach?
mixes the food with acid and enzymes to break it down
-contracts muscular walls to push food around and mix with acid and
-produces pepsin (protease enzyme)
-produces hydraucloric acid (kills bacteria and give the right ph for protease to work)
What does the liver do?
- produces bile
-filters the blood in the body and break down poisonous substances such as alcohol
What does the large intestine do?
-absorbs excess water and salts from undigested foods into the body which leaves behind feces
-producing and absorbing vitamins
-get rid of waste products as feces (stored in the rectum until removed)
What does the pancreas do?
-produces enzymes to break down sugars, fats, starches and protein
pushes these enzymes into the small intestine in the form of pancreatic juices
What does the small intestine do?
-breaks down food
-absorbs digested food into the bloodstream
- gets rid of any unnecessary components
-produces digestive enzymes to aid digestion (lipase, amylase,sucrase,lactase, maltase, aminopeptidase, carboxypeptidase)
How is the small intestine adapted for absorption?
-long (5m), provides a very large surface area for absorption of the product of digestion
- villi and microvilli increase surface area (more absorption at a quicker rate)
- very good blood supply so bloodstream rapidly removes the products of digestion and increases the concentration gradient
- thin membrane, short diffusion distance
-mitochondria, any molecules which cannot be absorbed by diffusion are absorbed by active transport
What is the function of the alveoli?
-site of gas exchange
-expand during inhilation (taking in oxygen)
-shrink during exhalation (expeling carbon dioxide)
What is the function of the diaphragm?
contracts and relaxes to pull air into the lungs
What is breathing?
The process of moving air in and out of the lungs
What is respiration?
The chemical reaction that releases energy from glucose usually in the presence of oxygen.
What is gas exchange?
The exchange of gases between the alveoli and blood in the capillaries by the process of diffusion
describe the order of the respiratory system
When we breathe in, air passes down our trachea (windpipe) which then divides between our two bronchi, and from there further divides between the bronchioles. Eventually, the air reaches the alveoli which will then be diffused into the bloodstream by a process called gas exchange.
Describe how the blood moves through the heart and around the body
- Blood is carried to the heart through the vena cava (de-oxygenated)
- Blood moves through the right atrium to the right ventricle (de-oxygenated)
- Blood is pumped through the pulmonary artery to the lungs (de-oxygenated)
- Blood returns to the heart through the pulmonary vein (oxygenated)
- Blood moves from the left atrium to the left ventricle (oxygenated)
- Blood is pumped to the rest of the body via the aorta (oxygenated)
Name the 8 parts of the heart organ
- pulmonary arteries (de-oxygenated)
- vena cava (de-oxygenated)
- right atrium (de-oxygenated)
- right ventricle (de- oxygenated)
- aorta (oxygenated)
- pulmonary vein (oxygenated)
- left atrium (oxygenated)
- left ventricle (oxygenated)
Function of arteries
Take oxygen-rich blood away from the heart and to the body
function of veins
return oxygen-poor blood to the heart
Function of cappilaries
Where substances are exchanged between the blood and other organs for example:
-oxygen in the lungs
-digested foods in the small intestine
-oxygen and nutrients are exchanged for carbon dioxide and waste
Describe the arteries
- high pressure
- thick walls
- narrow lumen
- no valves
- thick layer of muscle to make them strong and elastic fibres to allow them to stretch and spring back
Describe the veins
- low pressure
- thin walls
- wide lumen (help blood flow despite low blood preassure)
- contains valves (prevent backflow)
- capillaries join to form veins
What 4 main components is blood made up of ?
- Plasma
- Platelet
- White blood cells
- Red blood cells
Properties of plasma:
- transports hormones and digested food products
- a yellow liquid
-carries red and white blood cells, glucose and amino acids, co2, urea (from the liver to the kidneys), proteins, antibodies and antitoxins produced by the white blood cells.
Properties of white blood cells:
- can ingest pathogens (phagocytosis)
- defend against disease
- produce antibodies (fight microorganisms)
- produce antitoxins (neutralise any toxins produced by the microorganisms)
- have a nucleus
properties of platelets
-no nuclei
-important for clotting
-helps heal wounds
properties of red blood cells
-biconcave disc shape (large surface area more room for oxygen)
- contains haemoglobin (binds to oxygen)
- carries oxygen
-no nuclei (more room for oxygen)
-contains lots of iron
Function of the flower in a plant
attract pollinators and contains the reproductive system
Function of the leaf in a plant
absorbs light for photosynthesis
Function of the roots in a plant
absorbs water +mineral ions and anchors the plant
Function of the stem in a plant
supports the plant and is involved in the transport of substances to other parts of the body e.g. water
How are water and mineral ions transported into the plant?
water is moved into the root hair cell by osmosis whilst mineral ions such as nitrates are moved in by active transport
function of epidermal tissues
cover the plant, protecting it and preventing loss of water. this layer is often transparent to allow for sunlight to pass through.
Function of palisade mesophyll
where photosynthesis occurs. contains cells packed tightly together with high numbers of chloroplasts for photosynthesis to take place.
Function of the spongy mesophyll
layer has lots of air spaces for diffusion of gases
Function of waxy cuticle in plant
helps to reduce water loss
Function of stomata
small holes often on the underside of the leaf that allow for the diffusion of gases into and out of the leaf