NUTRITION

Question 1

Vitamin A: uses + deficiency

Answer 1

-makes the pigment in the retina for vision
-found in beta-carotene, carrots
-poor eyesight

Question 2

Vitamin C: uses + deficiency

Answer 2

-essential part of collagen protein
-citrus fruits
-scurvy

Question 3

Vitamin D:

Answer 3

-made by body naturally in sunlight
-helps body absorb calcium

Question 4

Calcium:

Answer 4

-strengthens bones and teeth
-found in dairy + milk
-rickets

Question 5

FIBRE DEFICIENCY

Answer 5

Causes constipation
-food lacks bulk for muscles to push it through the alimentary canal

Question 6

Taking in more energy causes..

Answer 6

OBESITY!
-can cause diabetes and increase the risk of heart disease

Question 7

Taking in less energy than used…

Answer 7

STARVATION!
-body breaks down energy stores, damages the immune system and heart
-increasing risk of disease

Question 8

Iron

Answer 8

-needed to make haemoglobin, that helps carry oxygen
-found in red meats, liver, leafy greens

Question 9

Explain PERISTALSIS

Answer 9

1) PERISTALSIS is the mechanism that moves food along the alimentary canal
2) when the bolts reaches the oesophagus, the CIRCULAR MUSCLES contract behind the bolus, NARROWING the lumen behind the bolus
3)MEANWHILE, the longitudinal muscles CONTRACT, and cause the section of the oesophagus to reduce in length
4) when the circular muscles CONTRACT, the two muscles cause the bolus to be propelled forwards, and the waves of contractions continue along the oesophagus

Question 10

Flow of the breaking down of starch

Answer 10

AMYLASE breaks down the starch into MALTOSE sugars,
MALTASE breaks down the maltose into GLUCOSE

Question 11

Role of BILE

Answer 11

1) NEUTRALISING the stomach acid- the alkaline bile neutralises the acidic contents of the stomach passing through tot eh small intestine- ESSENTIAL for raising the pH to be optimal for the enzymes in the small intestine
2) EMULSIFYING LIPIDS- bile salts in the bile EMULSIFY large droplets of lipids into smaller ones, increasing the surface area to volume ratio to maximise reaction rate

Question 12

Where is bile produced, stored, released

Answer 12

LIVER —-> GALLBLADDER——> SMALL INTESTINE

Question 13

How is the small intestine adapted for absorption?

Answer 13

1) VILLUS + MICROVILLI: increase SA:V ratio
2) GOOD BLOOD FLOW from NETWORK OF CAPILLARIES - steepens the concentration gradient to maximise diffusion
3) ONE-CELL THICK WALLS: reduces the diffusion distance
4)LACTEAL RUNS THROUGH CENTRE OF VILLI- carries the glycerol and fatty acids away from the small intestine

Question 14

NINTRATES: plants

Answer 14

-used to make amino acids for protein synthesis in plants
DEFICIENY: poor growth + yellowing of leaves

Question 15

MAGNESIUM:PLANTS

Answer 15

-used to make chlorophyll for photosynthesis in plants
DEFICIENCY: leaves turn yellow

Question 16

POTASSIUM IONS: PLANTS

Answer 16

-needed for enzyme reactions of photosynthesis and respiration
DEFICIENCY: causes leaves to turn yellow with dead/brown spots

Question 17

XYLEM structure + function + direction

Answer 17

The XYLEM is a long, continuous vessel of dead cells, strengthened with the woody material, LIGNIN in their cell walls (impermeable to water).
The XYLEM is located on the INSIDE of the vascular bundle
The XYLEM transports WATER + DISSOLVED MINERAL IONS to the plant from the root
The xylem travels unidirectional, only transports water + minerals upwards, from root to shoot

Question 18

PHLOEM structure + function + direction

Answer 18

The PHLOEM has tubes, that are located on the outside of the vascular bundle
The PHLOEM transport sugars and amino acids across the plant, in all directions
This process of transporting substances around the plant is called TRANSLOCATION

Question 20

PHOSPHATE IONS: PLANTS

Answer 20

-used to produce DNA + cell membranes
-cause poor root growth + leaves turn purple