P1: Organisation Flashcards
Which cell structure in a leaf mesophyll cell is not found in a root hair cell?
Chloroplasts.
Name the cells in a leaf that control the rate of water loss.
Guard cells.
Describe the transport of water through a plant from the roots to the atmosphere.
Water is transported in xylem, then evaporates from leaves through the stomata.
What is an organ?
A group of tissues that work together to form a specific function.
How is the volume of water lost from the leaves controlled?
By the guard cells opening and closing the stomata.
Which scientific term describes the movement of water when it is taken in by the roots, transported up the plant and lost from the leaves?
Transpiration stream.
What is a tissue?
A group of cells that perform a similar function
What is the heart’s function?
To pump blood around the body.
What is the epidermis?
The outer layer of the plant.
What is an organ system?
A group of organs working together.
What is an organism made of?
Lots of organ systems all working together
What is an enzyme?
A biological catalyst.
What is an optimum level?
A particular level whereby the enzymes work best
What do digestive enzymes do?
Help to break down large food molecules into smaller, soluble molecules.
What causes an enzyme to denature?
If the temperature or pH is too high.
What does amylase do?
Helps break down starch into simple sugars
Explain the Lock and Key Theory.
1) Substrate collides with active site of enzyme and becomes attached. Active site has a complimentary shape to the substrate.
2) Enzyme catalyses breakdown of substrate
3) Products are released from the active site, enzyme molecule is unchanged and can be reused.
What do proteases do?
Break down proteins into amino acids.
What do lipases do?
Break down lipids into fatty acids and glycerol
Where is amylase made?
The salivary glands, the pancreas and the small intestine.
Where is protease made?
The pancreas, the stomach and the small intestine
Where is lipase made?
The pancreas and the small intestine
Where does amylase work?
Mouth and small intestine.
Where does protease work?
Stomach and small intestine.
Where does Lipase work?
Small intestine.
Where is bile made?
The liver
What does the stomach produce that allows Protease to work effectively?
Hydrochloric acid, which allows the stomach to maintain a low pH.
Where is excess bile stored?
Gallbladder.
What does bile do?
-Emulsifies fats, breaking them down into small droplets.
-Neutralises the hydrochloric acid from the stomach.
State the order of the digestive system.
Mouth, Oesophagus, Stomach, Small Intestine (simultaneously the Liver, Gallbladder and Pancreas), Large Intestine, Rectum, Anus.
State the function of the mouth.
Chews and breaks down food. (Ingestion and digestion).
State the function of the stomach.
Holds food while it is mixed with enzymes, and breaks food down
State the function of the oesophagus.
Food is pushed through it to the stomach by a series of contractions called peristalsis
State the function of the liver.
Processes blood containing the nutrients absorbed from the small intestine, and produces bile.
State the function of the gallbladder.
Stores excess bile made in liver, and sprays food in the small intestine with bile.
State the function of the Pancreas.
Creates and releases digestive enzymes that are sent to the small intestine.
State the function of the small intestine.
Long muscular tube that is split into 3 sections. Breaks down food using enzymes.
State the function of the Large Intestine.
Processes waste and absorbs excess water.
State the function of the rectum
An 8 inch chamber that receives waste from the large intestine and stores it.
State the function of the Anus.
The last part of the digestive tract that releases stool. Composed of 2 sphincters.
State the 4 components of blood.
Plasma, Red blood cells, White blood cells, Platelets.
State the function of plasma.
Transports waste carbon dioxide to the lungs, carries urea from the liver to the kidneys for excretion. Carries small, soluble products of digestion from the small intestine to individual cells.
State the function of platelets.
Start the clotting process at the wound site.
State the function of the red blood cells.
Pick up oxygen from the lungs and carry it to the cells where it is needed. Packed with haemoglobin. No nucleus so that there is more room for oxygen.
State the function of white blood cells.
Body’s defence system against microorganisms. Form antibodies, antitoxins, engulf and digest bacteria and viruses. Bigger than red blood cells.
Describe and state the function of the arteries.
Carry blood away from the heart. No valves, thick layer of muscle with narrow space inside. Blood flows at high pressure.
Describe and state the function of the capillaries.
Carries blood close to every cell in the body. Connects veins and arteries. No valves, walls are one cell thick, tiny vessels. Low blood pressure and slow speed of blood flow to allow the exchange of materials.
