Adaptations for nutrition 2.4

Question 1

What is an autotroph?

Answer 1

Organisms that use simple inorganic materials to manufacture complex organic compounds. i.e. plants and bacteria

Question 2

What is a chemotroph?

Answer 2

Use energy from chemical reactions (less efficient than photosynthesis) e.g bacteria

Question 3

What is a phototroph?

Answer 3

Use light to carry out photosynthesis. e.g photoplankton, plants

Question 4

What is a heterotroph?

Answer 4

Organisms that consume complex organic food material made by autotrophs. i.e. animals, fungi, some bacteria

Question 5

What are saprophytes?

Answer 5

Fungi and some bacteria. extracellular digestion

Question 6

What are holozoic heterotrophs?

Answer 6

Humans. Internal digestive system

Question 7

What are parasites?

Answer 7

Body louse (ectoparasite)
Tapeworm (endoparasite)

Question 8

How does saprophytic digestion work?

Answer 8

-Secrete enzymes onto food outside the body
- Absorb the soluble products across the cell membrane by diffusion
-Extracellular digestion

Question 9

How does parasitic digestion work?

Answer 9

-An organism that obtains nutrients from another living organism or host
-This causes harm to the host
-Highly specialised for its way of life

Question 10

How does holozoic digestion work?

Answer 10

-Ingest food and digested internally
-Indigestible parts egested

Question 11

What is ingestion?

Answer 11

Taking in food

Question 12

What is digestion?

Answer 12

Breakdown of large insoluble molecules into small soluble molecules to absorb into blood

Question 13

What is absorption?

Answer 13

Molecules and ions pass through gut walls

Question 14

What is assimilation?

Answer 14

Products of digestion are used by cells

Question 15

What is egestion?

Answer 15

Elimination of undigested food

Question 16

What is the serosa?

Answer 16

layer of connective tissues, reduces friction with other organs

Question 17

What is the circular and longitudinal muscle?

Answer 17

Contracts behind the bolus of food, produces peristaltic waves

Question 18

What is the submucosa?

Answer 18

Blood and lymph nodes remove products and nerves coordinate peristalsis

Question 19

What is the mucosa?

Answer 19

Secretes mucus (some regions secrete digestive enzymes)

Question 20

What is digested in the duodenum?

Answer 20

Protein-> peptides
peptides-> amino acids
starch-> maltose
lipids-> fatty acids and glycerol

Question 21

What is digested in the ileum?

Answer 21

polypeptides, dipeptides, disaccharides

Question 22

What adaptations does the small intestine have for absorption?

Answer 22

-very long with folded surface
-folds have villi and microvilli
-epithelium is one cell thick
-rich blood supply
-many mitochondria for ATP for active transport

Question 23

Where do the blood vessels in the villi lead to?

Answer 23

the liver

Question 24

What are the epithelial cells and their functions?

Answer 24

goblet cells-secret mucus
Absorptive cells- contain numerous mitochondria and a brush border of microvilli

Question 25

How do triglycerides diffuse across the epithelum?

Answer 25

-Fatty acids and glycerol diffuse as micelles
-Chylomicrons made by golgi body leave via exocytosis and diffuse into lacteal
-Pass through lymphatic system to bloodstream opening at thoracic duct

Question 26

What is glucose used for?

Answer 26

-Energy release in respiration
-Excess glucose stored as fat

Question 27

What are amino acids used for?

Answer 27

-Absorbed for protein synthesis
-Excess deaminated, converted to urea (remainder stored or used in respiration)

Question 28

What are lipids used for?

Answer 28

-Membranes + hormones
-Excess stored as fat