nutrition and digestion

Question 1

what is nutrition

Answer 1

the way an organism obtains its food

Question 2

what does autotrophic mean

Answer 2

describes organisms that can make their own food eg plants

Question 3

what are heterotrophs + 3 types

Answer 3

an organism that cant make its own food, herbivore, carnivore, omnivore

Question 4

what are the steps of digestion

Answer 4

ingestion, digestion, absorption, assimilation and egestion

Question 5

what is ingestion

Answer 5

food is taken into the alimentary canal through the mouth

Question 6

what is digestion

Answer 6

food is broken down into soluble pieces physically and chemically so they can be absorbed into the blood stream

Question 7

explain the two types of digestion

Answer 7

physical digestion: mechanical breakdown of food. chemical digestion: when enzymes break down food

Question 8

where does physical digestion occur?

Answer 8

mouth by the teeth grinding, oesophagus and intestines by peristalsis, stomach by churning and muscular movement

Question 9

where does chemical digestion occur

Answer 9

saliva in the mouth by the amylase, pepsin in the stomach, lipase in the small intestine

Question 10

what are the four types of teeth

Answer 10

incisors, canines, premolars, molars

Question 11

what is food called after leaving the mouth

Answer 11

bolus

Question 12

what chemical digestion occurs in the duodenum

Answer 12

bile which is made in the liver and pancreatic juice enter the duodenum, the bile emulsifies fats and neutralises acid

Question 13

what is bile

Answer 13

made of water, bile salts and bile pigments, no enzymes and produced from the remains of dead red blood cells

Question 14

what are the islets if langerhans

Answer 14

specialised cells in the pancreas which produce insulin which control blood sugar levels

Question 15

what occurs in the small intestine

Answer 15

digestion in the duodenum and absorption in the ileum

Question 16

what occurs during absorption in the ileum

Answer 16

amino acids, monosaccharides and water soluble vitamins pass from the villi into the blood capillaries by diffusion and are carried to the liver via the hepatic portal vein. fatty acids, glycerol and fat soluble vitamins pass from the villi to the lacteal by diffusion they are then eventually brought to the liver as they are dumped into the blood. by the subclavian artery.

Question 17

what are the functions of the large intestine/ colon

Answer 17

reabsorb water, forms faeces, produces b and k vitamins by symbiotic bacteria

Question 18

what are the four parts of the large intestine

Answer 18

caecum, appendix, colon and rectum

Question 19

what are the functions of the liver

Answer 19

metabolism, produces bile, detoxifies the body, stores vitamins and minerals, makes plasma proteins, produces heat, breaks down red blood cells and produces cholesterol

Question 20

Describe the. Mechanical digestion in the stomach

Answer 20

Food is churned and broken up by
peristalsis.

Question 21

Describe chemical digestion in the stomach

Answer 21

Gastric Juice which is secreted into the
stomach consists of: Mucus, HCL, Pepsinogen
■ Mucus- lines and protects the stomach from
digestive enzymes.
■ Hydrochloric Acid (HCL)– kills bacteria
and activates pepsinogen to pepsin. (pH1-2)
■ Pepsinogen is an inactive enzyme which
is activated by HCL to the active enzyme
Pepsin. Pepsin is a protease which breaks
down proteins into peptides.

Question 22

What is the pancreas’ role in digestion

Answer 22

Secretes pancreatic juice (contains enzymes and
sodium bicarbonate)
■ Pancreatic Juice is secreted into the pancreatic duct
which leads to the duodenum where it is released.

Question 23

Adaptions of the Ileum to its
Function:

Answer 23

■ Very Long (all food can be absorbed)
■ Numerous Villi and Microvilli (increase
surface area)
■ Lacteals/ Lymph system to carry fats
■ Rich blood supply to carry water soluble
products
■ Walls of villi are thin allowing rapid diffusion

Question 24

Fate of amino acids, glucose and water soluble vitamins once absorbed

Answer 24

Amino acids, Glucose, Water soluble Vitamins:
• Liver will store glucose, converting it to Glycogen, and
stores vitamins and release them when they are needed.
• Amino acids cannot be stored so if they are not used they
are broken down to form Urea in a process called Deamination.

Question 25

Fate of fatty acids, glycerol and fat soluble vitamins once absorbed

Answer 25

Fatty Acids, Glycerol and Fat soluble Vitamins:
• Once inside the lacteal the fatty acids and glycerol join
together to become lipids once again. The Lipids are
transported around the lymph system until it empties into
the blood at the Subclavin Vein. The lipids are now sent to the
liver to be processed

Question 26

The amount of food a person requires depends on:

Answer 26

Age (younger people need more food than older, growing, more active)
2 Activity (less food needed if you have sedentary lifestyle, more food
needed if more active lifestyle)
3 Gender (males need more food than females)
4 Health (immunocompromised people diff. food requirements.. etc.)

Question 27

Food is made up of what six chemicals

Answer 27

C, H, O, N, P, S

Question 28

What are the three types of carbohydrates

Answer 28

Monosaccharides, disaccharides, polysaccharides

Question 29

Monosaccharides

Answer 29

Single sugar units of 1 ring of carbons such as Glucose and Fructose.

Question 30

Disaccharides

Answer 30

Two single units of sugar/monosaccharides joined together such as Sucrose and Maltose.

Question 31

Polysaccharides

Answer 31

Many sugar units joined together i.e. Starch, Cellulose and Glycogen.

Question 32

Functions of Carbohydrates

Answer 32

Structural Carbohydrate: Cellulose is a structural carbohydrate as it is used for its strength and support in plant cell walls.

Metabolic Carbohydrate: Glycogen is a metabolic carbohydrate as it is used as an energy store found in the liver. It can be broken down for metabolism when needed

Cellulose = fibre.

Question 33

Testing for Carbohydrates

Answer 33

Testing for Starch: Add iodine and observe color change. Blue/black color indicates the presence of starch. Red/brown = no starch

Testing for Reducing Sugar i.e. Glucose: Add Benedict’s solution and heat to observe color change.
Brick red: glucose present
Blue: no glucose

Question 34

Structure of Lipids

Answer 34

Lipids are made up of 1 Glycerol + 3 Fatty Acids = Triglyceride. Phospholipids have one fatty acid replaced with a phosphate.

Question 35

Function of Lipids

Answer 35

Structural Lipids: Phospholipids make up the structure of the cell membrane.

Metabolic Lipid: Adipose tissue can be used as an energy store.

Functional Lipid: Myelin in nerve tissue helps transmit messages.

Question 36

Testing for Lipids

Answer 36

Rub the food on brown paper. Observe for a translucent spot to determine the presence of lipids.
A translucent spot indicates the presence of lipids.

Question 37

Structure of Proteins

Answer 37

Proteins are made up of long chains of folded amino acids. There are 20 different amino acids found in proteins held together by peptide bonds.

Polypeptide chains become folded to produce proteins.

Question 38

Function of Proteins

Answer 38

Structural Protein: Keratin gives strength to hair, nails, and skin. Myosin is a protein found in muscle.
Functional Protein: Haemoglobin carries oxygen in red blood cells.

Metabolic Protein: Enzymes control metabolic rate in the body. Hormones regulate metabolic activity

Question 39

Testing for Protein

Answer 39

Add Biuret’s Reagent and observe color change to determine protein presence.

Violet color indicates the presence of protein.
Blue - no protein

Question 40

Two types of vitamins

Answer 40

Water Soluble such as B and C
Fat Soluble such as A, D, E, and K

Question 41

Vitamin C - solubility, function, source, effect on deficiency

Answer 41

Solubility: water soluble
Function: Vitamin C is very important for the building and maintaining of connective tissue e.g. skin, blood vessels, bone, tendons, cartilage, ligaments, teeth, gums. (needed for the absorption of iron into body and immune system also)
Source: Citrus Fruits, Green vegetables

Question 42

Vitamin D - solubility, function, source, effect on deficiency

Answer 42

Solubility: Fat soluble
Function: Vitamin D is needed to absorb calcium and phosphate the intestines from our food thereby it is important for healthy teeth and bone formation and maintenance.
Source: fish oils, egg yolk, milk, skin makes Vitamin D in sunlight.
Deficiency: Rickets in children and Osteomalacia in Adults. (bones are deformed and weak, easily breakable)

Question 43

Minerals In Animals

Answer 43

Calcium and iron

Question 44

Minerals in Plants

Answer 44

Calcium and magnesium

Question 45

Water

Answer 45

❖Excellent Solvent and Medium for all Chemical reactions
❖Involved in chemical reactions (photosynthesis, respiration)
❖Transport (plasma in blood, cytoplasm in cell)
❖Regulates Body temperature by dispersing heat through the blood

Question 46

Source and function of calcium in animals

Answer 46

Source: Found in dissolved salts in Dairy Produce.
Function: Formation and Maintenance of healthy Bone and Teeth

Question 47

Source and function of iron in animals

Answer 47

Source: Found in Red Meat, Offal, Spinach, Dark Green Veg.
Function: Needed to produce Haemoglobin in R.B.C.’s to
transport oxygen around the body.

Question 48

Source and function of calcium in plants

Answer 48

Source: Found in dissolved salts in water in soil.
Function: Formation of Calcium Pectate in Cell walls.

Question 49

Source and function of magnesium in plants

Answer 49

Source: Found in dissolved salts in water in soil.
Function: Needed to produce chlorophyll structure which is
the green pigment involved in Photosynthesis.