Biology Organisation Jan 2018

Question 1

What is the definition of digestion?

Answer 1

The chemical and physical process of breaking down large insoluble molecules into small soluble molecules

Question 2

What are the 11 parts of the digestive system?

Answer 2

1. Salivary glands 2. Oesophagus 3. Stomach 4. Liver 5. pancreas 6. bile duct 7. gall bladder 8. small intestine 9. large intestine 10. rectum 11. anus

Question 3

What are the functions of the 11 parts of the digestive system

Answer 3

Salivary glands -To produce saliva which lubricates the
food making it easier to swallow.
Oesophagus - To move food along from the mouth to
the stomach using peristalsis.
Stomach - To churn and mix the food when releasing
acids which help to destroy pathogens.
Liver - To produce bile (food does not enter this organ).
Gall Bladder - To store bile (food does not enter).
Bile duct - To carry bile.
Pancreas - To produce enzymes (food does not enter
this organ).
Small intestine - To digest food with bile and enzymes.
it also absorbs small soluble products
of digestion and has villi to increase
surface area so diffusion is better.
Large intestine - To absorb water and salts from
digested food.
Rectum - To store faeces
Anus - To allow faeces to leave the body in the process
of defecation.

Question 4

What is peristalsis?

Answer 4

Waves of muscle (created by muscles relaxing and contracting) which occurs in the oesophagus, stomach and intestines.

Question 5

What are enzymes?

Answer 5

Enzymes are biological catalysts that increase the rate of reactions (these are not involved int the equation and are unchanged at the end). Enzymes are proteins made up of amino acids joined together and are synthesised by ribosomes.

Question 6

What is a substrate?

Answer 6

A substrate is a chemical of which an enzymes acts upon.

Question 7

What part of an enzyme is complementary to the substrate?

Answer 7

The active site.

Question 8

When an enzyme and substrate are together, what 2 names are given? What happens when they join?

Answer 8

Names - ‘Enzyme Substrate complex’ or the ‘Lock and
key theory’
What happens - 2 products are released from the
active site and the enzyme is
unchanged and can be used again.

Question 9

When an enzyme becomes too hot it becomes ………

Answer 9

Denatured.

Question 10

What happens to denatured proteins?

Answer 10

They lose the shape of their active site.

Question 11

What colours are blood on diagrams? What do these mean?

Answer 11

Oxygenated - Red

Deoxygenated - Blue

Question 12

In what direction do arteries and veins bring blood?

Answer 12

Arteries - away from the heart.

Veins - towards the heart.

Question 13

What side of the heart is deoxygenated and oxygenated blood pumped?

Answer 13

Deoxygenated - The right hand side (left in diagram)

Oxygenated - The left hand side (right in diagram)

Question 14

What are the 2 main arteries connected to the heart?

Answer 14

The Pulmonary Artery (Travelling to the lungs) and the Aorta (Travelling to the rest of the body).

Question 15

What are the names of the 4 chambers in the heart? What are they?

Answer 15

The atrium (left and right) - Upper chambers of the
heart surrounded by a thin
wall of muscle.
The ventricle (left and right) - Lower chambers of the
heart surrounded by a
thick wall of muscle.

Question 16

What separates atriums from ventricles and ventricles from arteries?

Answer 16

Valves

Question 17

What are the 2 veins connected to the heart?

Answer 17

The Vena cava (from the rest of the body) and the pulmonary vein (from the lungs).

Question 18

Which ventricle has a thick muscle wall and why?

Answer 18

The left ventricle has a thick muscle wall because it transports the oxygenated blood to the rest of the body and needs a bigger push to get it there where as the right only needs to get the deoxygenated blood to the lungs which is not that far.

Question 19

Starting from the Vena cava. Where does the blood flow?

Answer 19

Vena cava –> right atrium –> valve –> right ventricle –> valve –> pulmonary artery –> lungs –> pulmonary vein –> left atrium –> valve –> left ventricle –> valve –> aorta –> the rest of the body –> vena cava.

Question 20

What is a pathogen?

Answer 20

A disease-causing microorganism (e.g. a bacterium or a fungus).

Question 21

What is bile?

Answer 21

A green coloured liquid that gets released into the small intestine to help break down fats.

Question 22

What are lipids?

Answer 22

Fats or oils that are insoluble in water.

Question 23

What are arteries, veins and capillaries?

Answer 23

Artery - A large blood vessel that takes blood from the
heart.
Vein - A large blood vessel that takes blood towards
the heart.
Capillary - A small blood vessel that joins arteries and
veins. Substances pass through the capillary
walls to and from the surrounding cells
(capillary wall is only 1 cell thick).

Question 24

What is haemoglobin? What does it form?

Answer 24

Haemoglobin - the protein in a red blood cell that can
temporarily bind onto oxygen to carry it
around the body.
Product - Oxyhaemoglobin (haemoglobin + oxygen)

Question 25

What are antibodies and antigens?

Answer 25

Antibody - A protein produced by lymphocytes that
recognises pathogens and helps to clump
them together.
Antigen - A protein found on pathogens that your
antigens can see as foreign.

Question 26

What are the epidermis, Palisade mesophyll and spongy mesophyll?

Answer 26

Epidermis - The outer most layer of cells of a plant
Palisade mesophyll - Tissue found towards the upper
surface of leaves with lots of
chloroplasts for photosynthesis.
Spongy mesophyll - Tissue found towards the bottom
surface of leaves with spaces
between them to allow gases to
diffuse.

Question 27

What are the xylem and phloem?

Answer 27

Xylem - Dead plant cells joined together into long tubes
through which water flows during transpiration.
Phloem - living cells that carry sugars made in
photosynthesis to all cells of a plant.

Question 28

What is the meristem?

Answer 28

An area of a plant in which rapid cell division occurs, normally in the tip of a root or shoot.

Question 29

What is transpiration and translocation?

Answer 29

Transpiration - The gradual release of water vapour
from leaves to continue to the ‘pull’ of
water up to them from the soil.
Translocation - The movement of sugars made in
photosynthesis from the leaves of
plants.