Organisation Science Biology Flashcards
What are cells?
basic building blocks of all living organisms
What is a tissue?
group of cells with similar structure and function
What are organs?
Aggregations of tissues performing specific functions
What is an organ system?
group of organs that work together to perform a specific function
What does the stomach do?
digests food
What does the large intestine do?
absorbs water from undigested food leaving faeces
What do glands do?
Produce digestive juices
What does the liver do?
produces bile
What does the small intestine do?
Digests food and absorbs soluble food molecules
What do enzymes do?
they catalyse(speed up) specific reactions in living organisms due to the shape of their active site
What are digestive enzymes?
They convert food into small soluble molecules that can be absorbed into the bloodstream
What breaks down lipids?
lipase
What are lipids broken down into?
fatty acids
What breaks down proteins?
protease
What are proteins broken down into?
amino acids
What breaks down carbohydrates?
carbohydrase
What breaks down starch?
amylase
What is starch broken down into?
simple sugars (mainly maltose)
What is the purpose of bile?
- It emulsifies any large lipid globules in the food into an smaller droplets which increases the surface area of the lipid.
- It is an alkaline to neutralise hydrochloric acid from the stomach.
What solution do you add to test for sugar?
Benedicts
What solution do you add to test for starch?
Iodine
What are the 4 main chambers of the heart?
right atrium, right ventricle, left atrium, left ventricle
Deoxygenated Blood passes through the vena cava from the right atrium to the right ventricle and is pumped out to the lings through the pulmonary artery
Describe the transportation of oxygenated blood
The heart receives oxygenated blood through the pulmonary vein thenpasses through the left atrium to the left ventricle through the aorta and out to the body
Describe what happens when the heart pumps
Blood enters the heart via the atria
. Once filled with blood, the atria contract, forcing blood down into the ventricles below. When the ventricles contract, they force blood to exit the heart.
Structure of the respiratory system
The trachea, or windpipe, branches into two bronchi - one bronchus to each lung. The bronchi split into smaller branches and then into smaller tubes called bronchioles. Each bronchiole ends in a cluster of microscopic air sacs called alveoli.
3 types of blood vessels
arteries, veins, capillaries
role of arteries
transport blood away from the heart to the organs. They all carry oxygenated (contains oxygen) blood (apart from the pulmonary artery).
How are arteries adapted
- The walls have elastic fibres, allowing them to stretch and spring back.
- Artery walls have thick layers of muscle. This makes them strong and able to cope with the high pressure at which blood is pumped out by the heart.
Role of capillaries
move waste products out of cells and into blood and moves food and oxygen out of the blood and into the cells
How are capillaries adapted
The wall is only one cell thick allowing a short diffusion pathway, the walls are permeable to allow diffusion and carry blood close to cells
Rile of the veins
Veins form when capillaries join up after passing through the body. They transport deoxygenated blood (apart from the pulmonary vein) from the organs back to the heart.
How are veins adapted?
1.The walls are thinner than those found in the arteries as the blood is at a lower pressure.
2.Wider cross section than arteries
3. veins have valves to prevent the backflow of blood.
what does blood consist of
white blood cells, red blood cells and platelets
Role of white blood cells
fight infection
How are white blood cells adapted?
can change shape and has a nucleus
How are white blood cells adapted?
can change shape and has a nucleus
Role of blood cells
Red blood cells transport oxygen from the lungs to all body cells.
How is spongy mesophyll adapted
1.Spongy mesophyll tissue is packed loosely for efficient gas exchange.
2.The spongy mesophyll cells are covered by a thin layer of water.
3.Gases dissolve in this water as they move into and out of the cells.
Allows carbon dioxide to diffuse out of cell
Upper epidermis adaptions
Transparent so that light can pass through to the pallaside layer
Light intensity
The brighter the light, the greater the transpiration rate. Photosynthesis can’t happen in the dark
Temperature
the warmer it is the faster transpiration happens. When it’s warm, the water particles have more energy to evaporate and diffuse out of the stomata
the small openings on the undersides of most leaves through which oxygen and carbon dioxide diffuse in and out of
function of guard cells
regulate size of stomata, regulates gas exchange and water loss (due to transpiration)
