Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biology - Year 1 > 2.4 - Nutrition > Flashcards

2.4 - Nutrition Flashcards

1
Q

define autotrophic

A
  • an organism the produces its own food
  • manufactures complex organic compounds from simpler inorganic molecules (water and carbon dioxide)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

name the two types of autotrophic organisms

A
  • photoautotrophic
  • heterotrophic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is a photoautotroph ?

A

an organism which obtains its nutrition through photosynthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is a chemoautotroph ?

A

an organism that obtains its nutrition through inorganic molecules e.g. sulphur in absence of light

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

define heterotrophic

A
  • an organism that cannot produce its own food
  • obtains energy by feeding on organic compounds produced by other organisms
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is a saprotroph?

A

an organism that feeds by extracellular digestion e.g. fungi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

describe extracellular digestion by saprotrophs

A
  • releases enzymes which catalyse the breakdown of dead plant and animal material into simpler organic matter
  • absorb the products of digestion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is meant by the term ‘holozoic’ ?

A

describes a heterotrophic organism that internally digests food substances

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what does holozoic nutrition involve?

A

ingestion, digestion, absorption, assimilation, egestion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

define ingestion

A

the process by which organisms take food into their body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

define digestion

A

the processes by which large, insoluble, molecules are broken down into smaller, soluble molecules that can be absorbed across cell membranes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

name two types of digestion

A

mechanical digestion
chemical digestion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is mechanical digestion ?

A
  • type of digestion that involves physically breaking down food material into smaller pieces
  • increases the total SA for chemical digestion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is chemical digestion ?

A
  • type of digestion that involves breaking down large, insoluble molecules into smaller, soluble molecules using enzymes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is assimilation ?

A

the synthesis of biological compounds from absorbed simpler molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

define absorption

A

the movement of useful substances into the bloodstream

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

define egestion

A

the removal of undigested waste from the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

describe how unicellular organisms obtain nutrients

A
  • indigestion via phagocytosis
  • intracellular digestion (using enzymes) breaks down large insoluble molecules into smaller, soluble molecules
  • products of digestion pass into the cytoplasm by diffusion and active transport
  • indigested material removed by exocytosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what is a hydra ?

A

a small, multicellular, freshwater organism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

describe the structure of a hydra

A
  • basic, undifferentiated sac-like gut
  • single opening, surrounded by tentacles, that serves as a mouth and an anus
  • single gut cavity (enteron)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

outline the process of digestion in Hydra

A
  • hydrolytic enzymes secreted into the enteron by endodermis
  • extracellular digestion partially digests food molecules
  • partially digested food transported via phagocytosis into endodermal cells where intracellular digestion takes place
  • undigested material egested from the enteron via single opening
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what type of diet is the human gut adapted to ?

A

an omnivorous diet consisting of plant and animal matter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

state the names of the different layers of the gut wall

A
  • epithelium
  • mucosa
  • submucosa
  • muscle layer
  • serosa
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what is epithelium ?

A

a single layer of cells that line the gut wall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

describe the structure of the mucosa layer of the gut wall

A
  • mucous membrane lining the gut wall
  • contains glands that secrete digestive enzymes, mucus and an acid or alkaline liquid that provides an optimum pH
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

describe the structure of the sub-mucosa layer of the gut wall

A
  • layer of connective tissue below mucous
  • contains blood vessels and lymph for the transport of digestion product and glands that secrete an alkaline fluid
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

describe the muscle layer of the human gut

A

a layer of circular and longitudinal muscles beneath submucosa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

explain the action of circular and longitudinal muscles in peristalsis

A
  • contraction of circular muscle behind bolus of food
  • relaxation of longitudinal muscle in front forces food down towards stomach
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

what is the serosa ?

A

the tough, protective layer around the gut

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

what is the buccal cavity?

A

the oral cavity through which food enters the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

what type of digestion takes place in the buccal cavity ?

A

mechanical (mastication)
chemical digestion of starch (amylase)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

describe the function of salivary glands

A

secrete amylase, mineral ions, and mucus into buccal cavity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

what is the function of the oesophagus ?

A

carries food from the buccal cavity to the stomach via peristalsis

34
Q

describe the process that takes place in the stomach

A

mechanical digestion (churning)
chemical digestion of protein

35
Q

what are the glands found in the stomach called ?

A

gastric glands

36
Q

describe the function of gastric glands

A

secrete endopeptidases, hydrochloric acid and alkaline mucus into the stomach

37
Q

what is the role of the liver?

A

secretes bile into the small intestine via the gallbladder and bile duct

38
Q

describe the composition and function of bile

A
  • bile salts and an alkaline fluid
  • neutralises stomach acid providing ideal stomach acid, providing pH for lipase
39
Q

what are the two main divisions of the small intestine ?

A
  • duodenum
  • ileum
40
Q

what is the duodenum?

A
  • the first section of the small intestine
  • hydrolyses proteins and lipids
41
Q

what is the ileum ?

A
  • the second section of the small intestine
  • main site of absorption of products of digestion
42
Q

what is the pancreas?

A

a large gland behind the stomach

43
Q

what is the role of the pancreas?

A

secretes enzymes and an alkaline fluid into the duodenum via pancreatic duct

44
Q

what is the function of the colon (large intestine)

A

reabsorbs water and minerals from the waste material

45
Q

what is the rectum ?

A

the segment of the large intestine that stores faeces prior to egestion

46
Q

which enzymes are involved in carbohydrate digestion?

A
  • amylase - in saliva and pancreatic juice
  • maltase, sucrase, lactase - on membrane of epithelial cells for small intestine
47
Q

which enzymes are involved in protein digestion ?

A
  • endopeptidases - hydrolyse non-terminal peptide bonds to form smaller proteins for (increases SA for exopeptidases )
  • exopeptidases - hydrolyse the terminal peptide bonds to form dipeptides and amino acids
48
Q

give 2 examples of endopeptidases

A
  1. trypsin
  2. pepsin
49
Q

how is trypsin produced ?

A
  • secreted by the pancreas as inactive trypsinogen
  • enterokinase converts inactive trysinogen into active trypsin in the duodenum
50
Q

what is the inactive form of pepsin ?

A

pepsinogen

51
Q

where is pepsinogen secreted from ?

A

gastric glands

52
Q

describe how inactive pepsiongen is converted into active pepsin

A

hydrochloric acid converts inactive pepsinogen into active pepsin

53
Q

where are lipids digested ?

A

small intestine

54
Q

what must happen before lipids can be digested ?

A
  • they must be emulsified by bile salts (produced by liver)
  • this breaks down large fat molecules into smaller soluble molecules (micelles) increasing SA
55
Q

how are lipids digested ?

A

lipases hydrolyse lipids into monoglycerides, fatty acids and glycerol

56
Q

where are lipases found ?

A

in pancreatic juice

57
Q

state the processes by which absorption takes place in the ileum

A
  • simple diffusion
  • facilitated diffusion
  • active transport
  • osmosis
58
Q

which molecules are absorbed by simple diffusion in the ileum ?

A

monoglycerides, fatty acids and glycerol

59
Q

why can monoglycerides, fatty acids and glycerol be absorbed via simple diffusion ?

A

they are non-polar so can easily diffuse across the membrane of epithelial cells

60
Q

what happens to monoglycerides, fatty acids and glycerol once they are absorbed into cells ?

A
  • they are reformed into triglycerides
  • absorbed into the lacteals
  • transported via lymphatic system into the blood
61
Q

how are amino acids absorbed from the lumen of the gut ?

A

active transport into epithelial cells then into bloodstream by facilitated diffusion

62
Q

which molecules rely on co-transport from the lumen of the gut into the cytoplasm of the epithelial cells ?

A

glucose and other monosaccharides

63
Q

explain how sodium ions are involved in co-transport

A
  • sodium ions are actively transported out of the cell into the lumen creating a diffusion gradient
  • nutrients are then taken up into cells along with Na+ ions
64
Q

how do monosaccharides pass from the epithelial cells into the blood stream ?

A

via facilitated diffusion

65
Q

what are herbivores ?

A

animals that only eat plant material

66
Q

describe the adaptations of herbivores to a high cellulose diet

A
  • long gut
  • lower jaw moves on a circular plane
  • horny pad on upper jaw
  • specialised dentition for grinding tough plant material
67
Q

describe how the dentition of a herbivore is adapted to its diet

A
  • small flat incisors on lower jaw only - cutting plant material on upper horny pad
  • diastema between incisors and premolars - enables manipulation of food by tongue
  • premolars & molars - large SA and ridged enamel (cusps) for biting and grinding plant material
68
Q

what are ruminants ?

A

mammals that digest plant material slowly in a specialised four-chambered stomach and regurgitates it to chew it again, enabling the efficient breakdown of cellulose

69
Q

name the four chambers of a ruminants stomach

A
  • rumen
  • reticulum
  • omasum
  • abomasum
70
Q

describe the rumen

A
  • 1st stomach
  • contains mutualistic bacteria that are able to hydrolyse cellulose into glucose
71
Q

what is a carnivore ?

A

an animal that only preys on and eats animal matter

72
Q

describe the adaptations of carnivores to a high protien diet

A
  • short gut
  • powerful jaw muscles
  • specialised dentition for cutting and tearing meat
73
Q

describe how the dentition of a carnivore is adapted to its diet

A
  • sharp incisors (tear flesh from bone)
  • large, backwards facing canines (grip and kill prey)
  • sharp carnassials ( modified premolars and molars) - to slice and shear meet off of bone
  • molars with sharp flattened edges to crush bone
74
Q

what is a parasite ?

A

an organism that lives in or on a host and takes nourishment at the expense of the host

75
Q

name the two types of parasite

A

ectoparasite (inside)
endoparasite (on)

76
Q

what are ectoparasites ? give an example

A

parasites that live on the host e.g. Head louse

77
Q

what are endoparasites? give an example

A

parasites that live in the host e.g. pork tapeworm

78
Q

how dos the head louse feed and transfer from one host to another?

A
  • feeds by sucking blood from the hosts scalp
  • transfers between hosts by direct contact
79
Q

where does the pork tapeworm live ?

A
  • primary host = adult tapeworm lives in the human gut
  • secondary host = larval form can develop in pigs
80
Q

how can humans and pigs become infected by the pork tape worm ?

A
  • humans consume uncooked pork (containing larval forms of tapeworm)
  • pigs ingest contaminated faeces
81
Q

how does the pork tapeworm feed?

A

absorbs pre-digested nutrients in the gut through its cuticle

82
Q

how is the pork tapeworm adapted to living in the gut?

A
  • thick cuticle
  • long thin body = large SA:V for absorption
  • scolex has strong suckers and hooks = attachment to gut wall
  • secretes anti-enzymes = prevent its digestion by host enzymes

Biology - Year 1 (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions