Organisms Exchange Substances with their Environment (Exchange)

Question 1

Ingestion

Answer 1

Taking in food

Question 2

Physical digestion

Answer 2

Breaking large food pieces into small pieces mechanically (teeth/stomach muscles/churning) increase surface area

Question 3

Chemical digestion

Answer 3

Breakdown of large insoluble molecules to small soluble molecules using enzymes/hydrolysis

Question 4

Absorption

Answer 4

Taking in the products of digestion, from the lumen of the small intestine into the blood stream

Question 5

Assimilation

Answer 5

The process by which nutrients fro foods are taken into the cells of the body after the food has been digested and absorbed

Question 6

Egestion

Answer 6

Removal of faeces form the body

Question 7

Breakdown of starch

Answer 7

1. Mouth with Salivary amylase = Maltose

2. Small intestine with Pancreatic amylase = maltose

Question 8

Breakdown of Protein

Answer 8

1. Stomach with Protease = Amino acids

2. Small intestine with Protease = Amino acids

Question 9

Breakdown of Maltose

Answer 9

1. Small intestine with Maltase = Glucose

Question 10

Breakdown of Lipids

Answer 10

1. Small intestine with Lipase = Monoglyceride + 2 fatty acids

Question 11

Carohydrate digestion

Answer 11

Amalyse hydrolyses alternate glycosidic bonds of starch molecule. Then maltose is hydrolysed into the monosaccharide a-glucose by maltase

Question 12

Membrane-bound disaccharidases

Answer 12

Disaccharidases that are attached to the membrane to further increase area that enzymes can work

Question 13

Lipid digestion

Answer 13

Hydrolysed by lipases to produce a monoglyceride and fatty acids. Pancreas, Ester bond, Micelles, Bile salts, Emulsification

Question 14

Micelles

Answer 14

Are the products of lipase digestion that remain in association with the bile slats to form structures

Question 15

Emulsification

Answer 15

Two immiscible liquids, one of which is dispersed as small droplets within the other, is produced

Question 16

Bile salts

Answer 16

Are biological detergents that the liver normally secretes into the duodenum to solubilise ingests fats

Question 17

Protein digestion

Answer 17

Hydrolysed by peptidases, Endo = middle, Exo = terminal

Question 18

Endopeptidase

Answer 18

First protease to work on proteins, (hydrolysis of peptide bonds between amino acids in the centre of a protein). Makes more terminal amino acids available

Question 19

Exopeptidase

Answer 19

Second protease to work on proteins, (hydrolysis of peptide bonds at terminal amino acids). Releasing single amino acids and dipeptides

Question 20

Dipeptidases

Answer 20

Hydrolyse the bond between the two amino acids of a dipeptide. Are membrane-bound, part of the epithelial cells lining the ileum

Question 21

Membrane bound dipeptidases

Answer 21

Dipeptidases that are attached to the membrane to further increase area that enzymes can work

Question 22

Ileum

Answer 22

The last part of the small intestine

Question 23

Food digested in the ileum

Answer 23

Starch, maltose, protein, triglycerides

Question 24

Absorbtion of glucose (1)

Answer 24

Sodium ions are co-transported by facilitated diffusion with glucose. Amino acids are also co-transported by facilitated diffusion with Na+ ions. Co-transported proteins on the membrane are involved. CHANNEL PROTEINS

Question 25

Absorbtion of glucose (2)

Answer 25

Na+ ion are actively pumped out of the epithelial cells across the plasma membrane into capillaries. From a low concentration to a high concentration ATP is used. Energy needed for active transport. CARRIER PROTEINS

Question 26

Absorption of glucose (3)

Answer 26

The amino acids or glucose pass out of the cell to the capillaries by facilitated diffusion

Question 27

Microvilli

Answer 27

Tiny finger-like projections from the cell-surface membrane of some animal cells

Question 28

Chylomicrons

Answer 28

Contains triglycerides, cholesterol, and other lipids, leave epethelial cell in exocytosis

Question 29

Lacteals

Answer 29

J

Question 30

Facilitated diffusion

Answer 30

Passive transport of molecules across a membrane, with the help of transmembrane proteins

Question 31

Lactose Intolerance

Answer 31

Not able to hydrolyse lactose
Water potential in lumen of SI falls
Water moves out of epithelial cells and capillaries to capillaries
Eventually move to large intestine

Question 32

Unbroken lactose causes what

Answer 32

Bloating, diarrhoea and cramps

Question 33

Bacterial fermentation causes what

Answer 33

Methane to form