Topic #2: Organisation (Paper 1) Flashcards
Explain the hierarchy of cells.
Cells make tissues
Tissues form organs
Organs collect to make organ systems, which keep us alive.
At what temperature do human enzymes denature?
40 degrees celcius
What happens in a nephron?
All the substances are filtered out of the blood and nephrons remove urea and excesses, putting the necessary molecules back into the blood.
What is an enzyme?
A biological catalyst that has an optimum pH and temperature.
Name the 3 digestive enzymes and what they digest.
Amylase- Breaks down starch into sugars
Lipase- Breaks down fats into fatty acids and glycerol
Protease- Breaks down proteins into amino acids
How do enzymes work?
The substrate fits into the active site like a lock and key to break it down.
Where is bile made and what is it?
Bile is an alkali (to neutralise stomach acid) made in the liver that emulsifies fat to turn it into small droplets with a larger surface area.
What does a pacemaker do?
Sends electrical impulses to the heart telling it to beat if it misses a beat.
What do veins, arteries and capilliaries do?
Vein- transport deoxygenated blood
Arteries- carry fresh blood around to capillaries
Capillaries- tiny arteries to carry blood to muscles
What does plasma carry in the blood?
Proteins and other chemicals
What do red blood cells contain?
Haemoglobin (transports oxygen)
What type of blood cell are antigens found in?
White blood cells
What do platelets do?
Encourage clotting of the blood
What happens in coronary heart disease?
Fats and cholesterol build up in lumps, blocking main arteries and limiting blood flow and a lack of oxygen to the heart.
How can you replace faulty valves?
Biological valves or mechanical
What are myelomas and how do they appear?
Cells that cannot stop multiplying- genetic code to stop is disabled, they form tumours.
What is a benign tumour?
A tumour specific to one region
What is a malignant tumour?
A tumour that spreads and invades nearby tissues, multiplying further and sapping blood supplies
Explain the formation of a leaf
Waxy cuticle, upper epidermis, palisade mesophyll, spongy mesophyll, lower epidermis, stomata + guard cells.
How do temperature, humidity, air flow and light intensity affect the rate of transpiration?
Higher temp. = Higher rate
Higher humidity = lower rate
More air flow = Higher rate
Higher intensity = Higher rate
What happens in the pancreas?
Protease, lipase and amylase are released into the small intestine
What does the large intestine do?
Absorb water
What occurs in the stomach?
Bacteria killed by acid
right pH for enzymes to work in
Protease (pepsin) produced
Where is the digested food absorbed?
The small intestine
