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Digestion Flashcards

1
Q

Nutrition

A

Way in which organisms obtain complex organic molecules
Raw materials from food help build and maintain structures

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2
Q

autotrophic nutrition

A

Organisms make their own food from single inorganic raw materials, CO2 and water into organic materials

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3
Q

Photoautotrophic organisms

A

Use light as energy source and perform photosynthesis
Green plants, some protocistor and some bacteria - type of nutrition is holophytic

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4
Q

Chemoautotrophic organisms

A

Uses energy from chemical reactions - or prokaryotes and perform chemosynthesis
Less efficient than photosynthesis and organisms that do this are no longer dominant life forms

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5
Q

Heterotrophic nutrition

A

Organisms cannot make their own food and consume complex organic molecules produced by autotrophs- consumers
Either eat autotrophs or organisms that have eaten autotrophs
Eg. Animals, dependent on producers for food
Animals, funky, some protoctista and some bacteria

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6
Q

saprotrophic nutrition

A

Used by all fungi and some bacteria
Saprotrophs feed on dead or decaying matter
No specialised digestive system secrete enzymes onto food material outside body for extracellular digestion
Absorb soluble products of digestion across the cell membrane by diffusion and active transport

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7
Q

Decomposers

A

Microscopic sapotrophs and are important in decaying leaf litter and recycling nutrients
Eg. Rhizopus

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8
Q

Rhizopus
process
fungal hyphae

A

1) Enzymes secreted from the tip of hypha digests the substrate ( organic matter which fungus grows and feeds)

2) Product absorbed and transports through mycelillum and enzymes perform extracellular digestion

3) nutrients absorbed back into fungal hyphae

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9
Q

Parasitic nutrient

A

obtaining nutrition from another living organism, the host

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10
Q

parasites
Endo, ecto

A

Endoparasites live in body of host, while Ectoparasites live on its surface
Parasites host always suffers some harm, often death
Parasites adapted in many ways - highly specialised for way of life Eg. Tapeworm , Head lice, potato blight, plasmodium

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11
Q

Holozoic nutrition

A

Nutrition used by most animals
Ingest food digest and egest indigestive remains
Food processed inside body in a specialised digestive system. In material absorbed into body tissues and used by cells

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12
Q

nutrition in unicellular organisms
eg amobea

A

Eg Amobea uses holozoic nutrition
Single sound organisms with large surface area:volume
Obtain all nutrients they need by diffusion, facilitated diffusion, active transport across cell membrane
Take in larger molecules and microbes by endocytosis into food vacuoles, fuse with lysosomes and contents digested by lysosomal enzymes
Products of digestion absorbed into cytoplasm and indigestible remains are egested by Exocytosis

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13
Q

Nutrition in multicellular organisms
stinging cells

hydra

A

single body opening- eg. Hydra
2 layers cells: On ectoderm and endoderm, separated by jelly layer (contain network nerve fibres)
Tentacle surrounding, only open body opening
Tentacles extend and when small organisms brush against tentacles , stinging cells discharged and paralyse prey
Move prey through mouth into hollow body cavity

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14
Q

Endodermal cells

A

Some secrete protease and lipase; Prey digested extracellularly and products absorb into cells
Other are phagocytic and engulf food particles (digest in food vacuoles)
Indigestible remains are egested through the mouth

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15
Q

tube gut

A

Tube with two openings, distinct anterior and posterior and digestive system. That mouth and indigestible waist like egested at the anus

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16
Q

human digestive system
food must be digesed

A

Food must be digested because:
Molecules are insoluble and too big to cross membrane and be absorbed into blood
Polymers must be converted to monomers so they can be rebuilt into molecules needed by body cells

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17
Q

peristalisis

A

how food is moved across digestive system
- longitudinal muscles contract to push food forwards then relax
- Circular muscles contract behind the bolus then relax; waiver contraction pushes the bolus down

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18
Q

functions of the digestive sstem

A

Ingestion- Taken food into body through buccal cavity
Digestion- Breakdown of large and solid ball into soluble molecules small enough to be absorbed into blood
Absorption- Passage of molecules through gut wall into blood
Egestion- Elimination of waste not made by body

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19
Q

chemical digestion

A

Digestive enzymes, bio, stomach acid contributes to breakdown food

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20
Q

mechanical digestion

A

Cutting and crushing by teeth and muscle contraction of gut wall - increases surface area so enzymes can act

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21
Q

function of mouth

A

Ingestion, digestion of starch and glycogen

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22
Q

function of oesophagus

A

Carriage of food to the stomach

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23
Q

function of stomach

A

Digestion of proteins

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24
Q

function of duedenum

A

Digestion of carbohydrates, fats and proteins

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25
function of ileum
Digestion of carbohydrates, fat, protein; absorption of digested food and water
26
function of colon
Absorption of water
27
function of rectum
Storage of faeces
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function of anus
Egestion
29
Structure of gut wall
4 layers of tissue surrounding cavity (lumen) serosa Muscle submucosa Mucosa
30
serosa
Outermost layer, tough connective, protecting gut wall. Gut moves while processing food at Serosa reduces friction (peritoneum) with other abdominal organs
31
muscle
Two layers in different directions Inner - circular muscle Outer- longitude or muscle They make coordinated waves of contraction (peristalsis) Behind boiler food, circular muscles contract and longitudal on muscles relaxed, pushing food along
32
submucosa thin layer
thin layer of connective tissues, containing blood and lymph and vessels - remove absorbed products of digestion and nerves that coordinate peristalsis
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mucosa epithelium
Into most layer and lines the gut wall Epithelium secrets mucus lubricating and protecting mucosa. In some regions of the gut it secrets digestive juices and in others, absorbs digested food
34
buccal cavity- mouth saliva
Food mixed with saliva by the tongue and chewed by teeth Food surface area increases, giving enzymes more access
35
saliva in mouth contents
contains: - Amylase, Beginning digestion of converting glycogen into maltose - HCO3- and CO32- ions, P H of saliva varies between 6.2- 7.4 but optimum pH of salivary amylase is 6.7-7.0 - mucus, lubricating foods passage - mucin, glues food together
36
oesophagus
Carries food to the stomach. Shows tissue layers in simplest form Bolus- food swallowed
37
Stomach
Food enters and kept there by contraction of two sphincters 2dm3, food stays for several hours Stomach wall muscles contract rhymically and mix food with gastric juice- secreted by glands in stomach walls
38
gastric juice
secreated from glands in depressions in mucosa- gastric pit
39
Gastric pit
- entrance to gastric pit at top - mature goblet cells - submucosa - Epithelial layer - Oxyntic cell - immature mucus cells - gastric pit - Zymogen/ chief cell
40
Mature mucus secreting goblet cells
Mucus secreted by goblet cell at the top of the pit forms a lining, protecting stomach wall from enzymes and lubricates food
41
Oxyntic cell
secreates HCL Hydrochloric acid lowers PH of stomach contents to PH2 for enzymes. kills bacteria in the food
42
Zymogen/ chief cell
secreates enzymes Peptidases, secreted by Zymogen at base of gastric pit pepisinogen (inactive enzyme) is secreated and activated by H+ ions to pepsin, an endopeptidase, hydrolyses protein to polypeptides
43
small intestine 2 regions
2 regions: Deodenum, Ileum Relaxation of the pyloric sphincter at base of stomach allows partially digested food into the deodenum, little at a time now everything is great deodenum receive secretions from liver and pancreas. pH of 8-9
44
Bile
Made in liver, stored in Gallbladder, passes through bile duct into deodenum - no enzymes - contains bike salts, amphipahic Emulsifies liquids by lowering surface tension and brake large globules into smaller ones- increase surface area and meat digestion by lipase more More alkaline and neutralises acid and food coming from stomach provides suitable pH for enzymes in small intestine
45
pancreatic juice islet
For created by Islet cells- exocrine glands in pancreas, enter deodenum through pancreatic duct
46
crypts of Lieberkühn food coming from
Food coming from stomach is lubricated by mucus, neutralised by alkaline secretions from cells at base of crypts of lieberkühn/ Brunner's gland
47
Ileum syntesise digestive
Epithelial cells lining the ileum have finger like projections called Villi which synthesised digestive enzymes: - Endopeptidase and exopeptidase - carbohydrates
48
Endopeptidases and exopeptidases
- Peptidases are secreted by villas epithelial cells and digestion continues in the gut lumen - Dipeptidases in cell surface membranes digest dipeptides to amino acids
49
carbohydrates
Carbohydrates are created and digestion continues in the gut lumen Carbohydrates in cell surface membrane digest disaccharides into monosaccharides Some disaccharides absorbed so their digestion is intracellular Amylase hyrdolyses starch and glycogen to maltose
50
Digestion of protein
protease, peptidase Digested into polypeptides and dipeptides into amino acids
51
Endopeptidases within
Hydrolyzes peptide bonds within the protein molecule
52
Exopeptidases at the end
hydrolyses the terminal peptide binds at end of shorter polypeptides
53
Absorption
occurs mainly in small intestine by diffusion, facilitated diffusion and active transport Active transport needs ATP
54
Ileum- absorption cells are produced
Lining folded On the surface of folds - villi have projections- microvilli Increase SA for absorption Self are produced at base of glands and move out to replace old cells sloughed off by the food
55
Section of ileum wall
Crypts of lieberkühn- gap between Epithilium- one cell thick Villi Capillary- ends Lacteal- middle Venule- carries blood to hepatic partalvein, middle bottom Artieole- first bottom Lymph vessel- last bottom Circular muscle Longitudinal muscle
56
villus
Inside Villus is a dense network of blood vessels They absorb digested food molecules Also lacteal- blind ended tube of lymphatic system, involved in absorption of lipids
57
fates of nutrients- glucose
Glucose is taken to body cells and respired for energy or stored as glycogen, in liver and muscle cells. The excess is stored as fat
58
fates of nutrients- amino acids
Amino acids taken to body cells for protein synthesis Excess cannot be stored so liver deaminates and converts NH2 groups to urea, Carried in blood and excluded at the kidney remains of amino acid molecules are converted into carbohydrate for storage or conversion to fat
59
large intestine undigested
Undigested food, mucus, bacteria and dead cells pass into the colon Colon wall has fewer villi in the ileum and these will have major role in water absorption
60
vitamin k and fulic acid - large intestine
Secreted by mutualistic microorganisms living in the colon, and minerals absorbed from the colon As material passes along:, water is absorbed and by the time it reaches the rectum, material is semi solid It passes along the rectum and is egested as faeces in process called defecation
61
adaptions for diet
When reptiles and amphibians ingest food they swallow it whole Mammals retain their food in their mouth while it is cut and chewed Mammals are the only vertebrates to have a palate separating the nasal and mouth cavities, so they can hold food in mouth and chew while breathing
62
carnivore
Eats only animals and so its diet is mostly protein Small intestine is short in relation to body length reflecting the ease with which protein is digested Large intestine is straight with smooth lining
63
herbivore
It's only plant material Smaller testing is long in relation to body length because plant material is not readily digested and a long gut allows enough time for digestion and absorption of nutrients
64
omnivore pouch
Gut length is intermediate A herbivore and omnivore has a pouch large intestine so it can stretch to accommodate larger volume of faeces produced in digesting plants- Much of which is cellulose Large instestine is also long with Villi where water is absorbed
65
Dentition
Food must be cut, crushed, ground or sheared Humans have incisors, canines, premolars and molars
66
Dentition of Herbivores
Plant cell walls are tough to eat as they contain cellulose and liggin and sometimes silica The teeth of Hebivores are modified so that the cells can't be thoroughly ground up before entering the stomach
67
Herberores - incisors and canine 1
Grazing Herbivore - incisors on lower jaw only Canine teeth are indistinguishable from the incisors Animal wraps his tongue around the grass and pulls it tight across the leathery 'dental pad' on upper jaw then lower incisors and canine slice through it
68
herbivore- diastema 2
Gap called diastema separates front teeth from premolars Tongue and cheeks operate in this gap, moving freshly cut grass to large grinding surfaces of the molars
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herbivore- molar 3
molars interlock- like a W into an M lower jaw moved side to side- produces circular grinding action in a horizontal plane. with time- Grinding services of teeth become worn, exposing sharp edged enamel ridges further increasing efficiency of grinding Teeth have opened unrestricted roots so they continue to grow throughout animals lives replacing material worn down
70
Herbivore- skull and muscles
Hibbard does not need strong muscles attached to its jaws because it's food is not likely to escape Its skull is relatively smooth, reflecting absence of sight for strong muscles to attach
71
Dentition of carnivores
They have teeth adapted for catching and killing prey, cutting or crushing bones and tearing meat
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Carnivores - incisors 1 grip and tear
sharp incisors grip and tear muscle from bone
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carnivore- canine 2 pierce sieze kill and tear
Canine teeth are large, curved and pointed for piercing and seizing prey for tearing muscles and killing
74
carnivore- premolars and molars 3 cut crush
Premolars and molars have cusps, which are sharp points that cut and crush
75
carnivore- carnassials 4 shear
Carnivals have pair of specialised cheek teeth called carnassials in each side They slide past each other like scissor blades, these shear the muscle off the bone Large and easily identifiable
76
carnivore- lower jaw 5
Lower Jaw moves vertically Carnivals open their doors very wide when they deal with prey and side to side movements could dislocate their jaw
77
ruminant
a cud chewing herbivore possessing a 'stomach' divided into 4 chambers largest-rumen, contains mutualistic microbes
78
rumen
chamber in the gut of ruminant herbivores, in which mutualistic microbes digest complex polysaccharides
79
Mutualism
A close Association of organisms from more than one species, providing benefits to both
80
Mutualistic microbes
Much of Herbivores food is cell war material, mainly cellulose Animals cannot make cellulase and cannot digest the beta glycosidic bonds in cellulose Therefore they rely on mutualistic microbes living in their gut to secrete the enzyme instead
81
What do mutualistic microbes include
Bacteria, fungi and protocista which live in the Rumen
82
Cellulose digestion 1
Grass is cut by the teeth and mixed with saliva to form the curd, swallow down the oesophagus to the rumen
83
The Rumen 2 fermented to
Chamber in which food mixes with microbes. Microbes secrete enzymes which digest cellulose into glucose Glucose is fermented to organic acids that are absorbed into the blood and are an energy source for cow Carbon dioxide and methane released as waste products
84
Cellulose digestion 3
Fermented grass passes to the reticulum and is reformed into cud. It is regurgitated into the mouth for further chewing
85
Cellulose digestion 4
Cud may be swallowed and regurgitated into the mouth several times
86
Cellulose digestion 4
Cut passes next into the omasum where water and organic acids made from fermented glucose are absorbed into the blood
87
Cellulose digestion 5
4th chamber -abomasum is the 'true' stomach, where protein is digested by Pepsin and at P H two
88
Cellulose digestion 6
Digested food passes to the small intestine, from where the products of digestion are absorbed into the blood Functions of large intestine are comparable with those of human
89
Parasites
An organism that obtains nutrients from another living organism or host, to which it causes harm They may live on or in an organism
90
Parasites in plants
Bacteria fungi viruses, nematodes and insects
91
Parasites in animals
Also parasited by Protoctistans, tapeworms and mites
92
Parasites in bacteria
By viruses called bacteriophages
93
pork tape worm
Taenia Solium It has no competition- cannot be predated upon Endoparasite
94
Pork tapeworm description
Ribbon like- shape allows plenty of space for host food to move past it Ten metres long And your end - scolex made of muscle carrying suckers and hooks But he has linear series of sections proglottids Rostellum
95
proglottids mature and terminal
mature proglittids- Contain uterus with embryos Terminal proglottids- Fall off and are discharged with the faeces
96
Tapeworms Lifecycle
Requires it to alternate between two hosts Primary host- human Secondary host - pig larval forms develop The peak becomes infected when food is contaminated with human faeces Human are infected by eating undercooked pork containing live larval forms
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how the tape worm survives hostile conditions in the gut
- Surrounded by digestive juices and mucus - Must withstand peristalsis - Experiences pH changes as it moves down the gut to the deunodum - Exposed to hosts immune system - If host dies parasite dies
98
Tapeworm structural modifications Scolex
Has suckers and a double row of curved hooks to attach it strongly to the duodenum wall
99
Tapeworm structural modification Cuticle
a thick body covering protecting it from the host's enzymes and immune system
100
Tapeworm structural modifications Enzyme inhibitors
It makes enzyme inhibitors which prevent the hosts enzymes digest in it
101
Tapeworm structural modifications Reduced gut
It has a very reduced gut; a large surface area to volume ratio lets it absorb pre digested food over its whole surface
102
Tapeworm structural modifications hermaphrodite
Each proglottid has male and female reproductive organs. Guts usually only has one tapeworm but each mature proglottid may contain forty thousand eggs - pass out of host body with faeces Lots of eggs increase chances of infecting secondary host
103
Tapeworm structural modifications Resistant shells
The eggs have resistant shells and survive until eaten by pig. Hatch and move through intestine wall into pig muscles remain dormant there until meat is eaten
104
harmful effects of pork tape worm
Adult tapeworm may cause little discomfort but long term infection may produce taeniasis - giving abdominal pains and weakness Can be treated with drugs If eggs are eaten directly - embryos can form cysts in various organs and damage surrounding tissue
105
Head lice
Pediculus ectoparasite Wingless insects. Fly and legs are poorly adapted to jumping and walking so they are transferred from one host to another by direct contact They die if removed from human
106
3 stages in Louse life cycle
Adult Louse lays eggs - hatch after 12 weeks into nymphs leaving nits, empty egg cases Nymph is like an adult but smaller Becomes adult after 10 days and feeds on blood
107
Absorption of amino acids into epithieal cells
Amino acids absorbed into epithelial cells by active transport and, as amino acids, they pass into capillaries by facilitated diffusion Water soluble and dissolving the plasma
108
Absorption of glucose
Glucose passes into epithelial cells with sodium ions by co-transport Move into capillaries sodium by active transport and glucose by facilitated diffusion and dissolving plasma Diffusion I'm facilitated diffusion are slow and not all the glucose is absorbed To prevent it leaving body in faeces, some is absorbed by active transport
109
Absorption of fatty acids
Fatty acids and monoglycerides diffuse into epithelial cells and into lacteals Lacteals are blindly ending lymph capillaries in the villi They are part of lymphatic system transport soluble molecules to the left subclavian vein near the heart
110
Absorption of minerals taken into the blood
minerals are taken into blood by diffusion, facilitated diffusion and active transport and dissolve in plasma
111
Absorption of vitamins
Vitamin B and C are water soluble and are absorbed into blood Vitamin A D and E are fat soluble and are absorbed into lacteals
112
autotroph
Organism that synthesises its own complex organic molecules from simpler molecules using either light or chemical energy
113
Heterotroph
Organism that obtains complex organic molecules by consuming other organisms
114
Saprotroph/ saprobiont
Organism that derives energy and raw materials for growth from extracellular digestion of dead or decaying material

Biology🔬🧬 (11 decks)

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