human nutrition (topic 7)

Question 1

describe what is meant by a balanced diet

Answer 1

Consuming all the nutrients needed by the body, in the correct amounts to maintain health. seven major nutrients:
carbohydrates
fats
proteins
vitamins, such as vitamin C and vitamin D
mineral ions, such as calcium and iron
fibre (roughage)
water.

Question 2

state main source and importance of carbs

Answer 2

pasta, bread, potatoes, fruit, vegetables
provides energy

Question 3

state main source and importance of fats

Answer 3

avocado, nuts, olive oil, oily fish
provide energy

Question 4

state main source and importance of proteins

Answer 4

meat, fish, eggs, beans, nuts
growth and repair

Question 5

state main source and importance of vitamin c

Answer 5

organces, red peppers, broccoli, kale
maintains healthy blood vessels, skin, cartilage and bones
helps with wound healing

Question 6

state main source and importance of vitamin d

Answer 6

salmon, cheese, eggs
helps to regulate the amount of calcium and phosphate in the body, necessary to keep teeth, bones and muscles healthy

Question 7

state main source and importance of iron

Answer 7

red meat, beans, nuts
production of haemoglobin for red blood cells

Question 7

state main source and importance of calcium

Answer 7

milk, sardines, broccoli, kale, okra, spinach
strengthens bones and teeth, and helps with muscle contraction and clotting of wounds

Question 7

state main source and importance of fibre

Answer 7

cereals, vegetables, fruit, brown rice, nuts, potatoes
helps digestion, and helps to move food and faeces along the gut
associated with lower risks of coronary heart disease, type 2 diabetes and bowel cancer

Question 8

state main source and importance of water

Answer 8

water and drinks
about 60% of body mass is water, and it is needed in almost every process

Question 9

rickets

Answer 9

deficiency disease caused by lack of vitamin d, bone pain weakness in the muscles bone loss with an increased risk of fractures and skeletal deformities

Question 10

scurvy

Answer 10

deficiency disease caused by lack of vitamin c, severe leg pain or joint pain tiredness weakness blue or red spots on the skin, which bruise easily swollen and bleeding gums

Question 11

order in which food flows through digestive system

Answer 11

alimentary canal: mouth, oesophagus,
stomach, small intestine (duodenum and
ileum) and large intestine (colon, rectum,
anus)

Question 12

state other parts of the body which are essential for digestion however food doesnt pass through

Answer 12

salivary glands
liver
gall bladder
pancreas.

Question 13

ingestion (in detail)

Answer 13

taking substances (food and drink) into the body through the mouth. once swallowed food is known as bolus, waves of muscle contraction in walls of oesophagus push bolus to stomach.

Question 14

digestion (in detail)

Answer 14

breaking food down into nutrients. Either physical digestion: breaking food into smaller pieces without any chemical change (happens in mouth, stomach)
chemical digestion: breaking down large insoluble molecules to small soluble molecules with help of enzymes (happens in mouth, stomach, small intestine)

Question 15

absorption (in detail)

Answer 15

movement of small food molecules and ions through the wall of the intestine into the blood. It happens in the small intestine.

Question 16

assimilation (in detail)

Answer 16

movement of digested food molecules from the blood into the cells of the body where they are used, becoming part of the cells. This process happens throughout the body

Question 17

egestion (in detail)

Answer 17

involves passing out food that has not been digested or absorbed. These materials leave the body as faeces. Faeces are stored in the rectum ready for you to go to the toilet. The faeces then pass through the anus.

Question 18

what is the purpose of physical digestion

Answer 18

increases the surface area of food for the action of enzymes in chemical digestion

Question 19

salivary gland describe purpose

Answer 19

produce saliva, secreted into mouth, mixes with food makes it easier to chew, saliva contains amalyse (breaks downstarch into simple reducing sugars)

Question 20

liver and gall bladder describe purpose

Answer 20

liver produces bile (Alkaline liquid that neutralises the acidic mixture entering the duodenum from the stomach, and emulsifies fats.) this substance is stored in gall bladder before released through bile duct to duodenum

Question 21

pancreas describe purpose

Answer 21

secrete pancreatic juice liquid that helps in chemical digestion of proteins fats and carbs, alkaline solution, helping to neutralise acid in food leaving stomach.

Question 22

what is bile

Answer 22

bile is a liquid produced by liver, stored in gall bladder, important for the emulsification of fat, thus it emulsifies fats into small droplets, increasing their surface area, allows lipase to digest these fats into fatty acids and glycerol more quickly
it can neutralise the acidic mixture of gastric juice and food as it enters the duodenum from the stomach. This is important because the amylase and trypsin there work best under alkaline conditions.

Question 23

what are the types of teeth present, in order from middle of mouth to end

Answer 23

incisors, canines, pre molars, molars

Question 24

incisors

Answer 24

Teeth with sharp, blade-like features, for cutting food

Question 25

canines

Answer 25

strong, pointed, for tearing food

Question 26

pre molars

Answer 26

Teeth with combined features of canines and molars for grinding and tearing food.

Question 27

molars

Answer 27

broad, flat surface, for crushing and grinding

Question 28

what are the structures present in human teeth

Answer 28

enamel, dentine, pulp, gum, blood vessels, cement, nerve

Question 29

enamel

Answer 29

the outer white layer of the tooth – the part you can see. It is the hardest part of the tooth and the hardest substance in the body.

Question 30

dentine

Answer 30

hard bone-like substance, but it is softer than enamel. Most of the tooth is made from dentine, which surrounds and connects to the pulp.

Question 31

pulp

Answer 31

forms the centre of the tooth. It contains blood vessels and nerves.

Question 32

nerves

Answer 32

In a tooth the nerve is sensitive to pressure, temperature and pain.

Question 33

cement

Answer 33

attaches the teeth to the jawbone

Question 34

gums

Answer 34

form a layer around the teeth helping to keep the teeth in place.

Question 35

how does stomach assist in physical digestion

Answer 35

the stomach, the muscular walls squeeze and churn the food as it mixes with hydrochloric acid, further reducing the size of food particles.

Question 36

role of chemical digestion

Answer 36

producing small soluble molecules that can be absorbed

Question 37

amalyse

Answer 37

starch-> maltose
secreted- salivary glands, pancreas
acts- mouth, small intestine

Question 38

maltase

Answer 38

maltose -> glucose
on the membranes of the epithelium lining the
small intestine

Question 39

protease

Answer 39

protein -> amino acids
pepsin- acts in stomach requires acidic enviornment
trypsin- acts in small intestine, requires alkaline conditions, passes from pancreas to duodenum where changed chemically to work in small intestine
secreted- stomach, small intestine
acts- stomach, small intestine

Question 40

lipase

Answer 40

fats -> fatty acids and glycerol
secreted- pancreas
acts- small intestine

Question 41

gastric juice

Answer 41

mixture secreted in the stomach, contains hydrochloric acid ph 1.5-3.5
1-provides an acid pH needed for the enzymes there to work.
2-It kills bacteria in food.
low ph of gastric juice, provides optimum ph for protease to work in stomach
causes denaturation of enzymes of harmful microorganisms in food

Question 42

where does absorption take place

Answer 42

of soluble food molecules- in small intestine
water- mostly in small intestine due to its structural adaptations however some of it is in colon

Question 43

what are adaptations of small intestine

Answer 43

villi, microvillus

Question 44

villi

Answer 44

tiny finger-like projections that increase the surface area of the small intestine.

Question 45

microvilli

Answer 45

cell membranes of the cells lining the surface of a villus are folded to form microvilli, further increasing the surface area needed for rapid absorption.

Question 46

structure of villus

Answer 46

has network of blood cappilaries inside it, close to epithelium surface for efficient absorption into blood of circulatory system of (amino acids and simple sugars and water)
capillary network wrapped around lacteal structure is responsible for the absorption of fats into the lymphatic system