Mammals as Consumers book 1 Flashcards
1
Q
How is a mammal classified as a mammal?
A
-They all have 7 vertebrates -All have 4 chambered hearts -They use lungs to breathe -They are warm blooded -Their body is covered with fur or hair -They suckle their young on milk (main one)
2
Q
What is nutrition necessary for?
A
Energy - necessary for all cells to function Growth - to make new cells (mitosis) Repair - to replace worn cells
3
Q
What are the 7 food groups?
A
Carbohydrates Proteins Water Fiber Vitamins Minerals Fats
4
Q
Why do we need carbohydrates?
A
Main source of energy Can be metabolised quickly
5
Q
Why do we need proteins?
A
Builds and repairs tissue
6
Q
Why do we need fats?
A
Stored as energy for later Acts as insulating layer
7
Q
Why do we need vitamins?
A
Consumed in small amounts for normal bodily growth, development and function (ie vitamin C helps immune system)
8
Q
Why do we need minerals?
A
Consumed in small amounts for body features (ie calcium necessary for bones)
9
Q
Why do we need fiber?
A
So that food can pass through our digestive track
10
Q
Why do we need water?
A
All chemical reactions in the body occur in water
11
Q
What are the 5 processes of digestion?
A
Ingestion, Digestion, Absorption, Assimilation, Excretion
12
Q
What is ingestion?
A
Putting food into the body
13
Q
What is digestion?
A
The physical and chemical processes of breaking down large pieces of food into small soluble pieces
14
Q
What is Absorption?
A
The process of small soluble food particles passing through the gut walls into the blood
15
Q
What is Assimilation?
A
When the small soluble food particles absorbed into the blood are diffused into individual cells to provide nutrients for the cells to perform normal cellular functions
16
Q
What is excretion?
A
When undigested food material is removed from the body through the anus
17
Q
What is the purpose of the teeth in a nut shell
A
To break large pieces of food into small pieces of food to INCREASE SURFACE AREA for enzymes
18
Q
What is the purpose of the the mouth?
A
- allows for food to be ingested into the body
- physicaly breaks down food as teeth break food down into smaller pieces
- chemical, salivary amylase is produced in the salivary glands breaking down starch into maltose
- saliva also contains mucin which moistens food so that is can go down the oesophagus easily
19
Q
What is the pH of the mouth? Why is it that pH?
A
6.4-7.4, OPTIMAL pH for salivary amalyse
20
Q
What are 4 main structures of the tooth?
A
Enamel, Dentine, Pulp cavity, cement
21
Q
What does the enamel do?
A
It protects the teeth and creates a hard biting surface for chewing, contains high concentration of calcium phosphate making it the hardest substance in the body
22
Q
what does the dentine do?
A
it give the tooth sensitivity to heat, acidity, pressure etc. because it is full of nerve endings
23
Q
what does the pulp cavity do?
A
it provides nutrition to the dentine and links nerves to brain
24
Q
what does the cement do?
A
The cement secures the tooth to the jawbone, covers the root of the tooth
25
What are the 4 types of teeth?
-Canines -Incisors -Premolars -Molars
26
What is the shape and function of the canines?
They are pointy and are designed to tear off chunks of flesh
27
What is the shape and function of the incisors?
They are broad faced and sharp and are used to slice food
28
What is the shape and function of the molars?
They are flat surfaced and are used to grind up food
29
What is the shape and function of the premolars?
They are pointy molars and are used to shred food
30
What are some features of a herbivore skull?
-well developed muscles for extensive chewing -side to side motion of jaw to crush and grind cellulose -large diastema to store more saliva so more salivary amylase digest more plant material -no canines as they don't have to grab hold of flesh -wide flat molars to grind plant material
31
What are some features of a carnivore skull?
-reduced facial muscles as there is no extensive chewing -up and down motion of jaw to slice food -long sharp curved canines to grab hold of flesh and rip -premolars to slice meat
32
what causes dental decay?
when the teeth are subject to higher acidity conditions than usual, this is caused by eating high pH foods such as juice etc. and also bacteria excrete acid by consuming sugar on your teeth, they easily decay the enamel as it is mainly calcium phosphate, this exposes dentine
33
What does the oesophagus do?
Connects the mouth to the stomach, control the speed which food goes into the stomach by peristalsis (no digestion occurs here)
34
What is peristalsis?
it is when muscles behind the food push food through the digestive system (oesophagus, small intestine etc.)
35
How does the stomach digest food?
It mechanically digests food by contracting its thick muscluar wall to break down food TO INCREASE SURFACE AREA TO VOLUME RATIO, chemically breaks down proteins by breaking it down into peptides because of pepsin
36
What is in stomach juices, what do they do and what adaptations does the stomach have to handle it?
Hydrochloric Acid (HCl) - increases the stomachs pH to a pH of 1-2, kill bacteria and other microbes on food that is ingested (pretty much cleans by killing microbes), has a mucus lining around gut wall that contains HCO3- ions that neutralise the acid, mucus lining also prevents HCl from burning stomach layer in first place Pepsin - digestive enzyme that breaks down proteins into peptides, doesn't digest gut wall (has protein in it so it can be digested) as the pepsin has an OPTIMAL pH of 1-2 so when the HCl neutralises the pepsin, it becomes DENATURED and can't digest proteins anymore protecting the gut wall
37
What produces stomach juices, where are they?
Gastric pits lined along the inside of the stomach wall
38
What kind of nutrients can the stomach absorb?
Nutrients that do not require digestion, ie alcohol
39
What chemical does the stomach produce that is necessary for production of red blood cell?
Intrinsic factor, needed for the absorbtion of B12
40
What and where are the sphincters located?
Cardiac sphincter - located at the top of the stomach, controls the influx of food from the oesophagus and controls the release of food back up the oesophagus Pyloric sphincter - located at the bottom of the stomach and controls the chyme that is released into the duodenum (bonus) Anal sphincter - controls the relase of faeces
41
What is a sphincter?
A ring of muscle
42
What are the 2 sections of the small intestine?
Duodenum - first part Illium - second part
43
What does the duodenum do?
It's primary role is to digest food with pancreatic juices that contain enzymes
44
What is Pancreatic juice?
It is an alkalane liquid (pH 7.5-8) that contains digestive enzymes (protease [breaks down proteins and peptides into peptides and amino acids], trypsin [breaks down peptides into amino acids], lipases [breaks down lipids into fatty acids], amalyse [breaks down starch into maltose] and maltase [breaks down maltose into glucose])
45
Why is the pH of the duodenum slightly basic?
The chime from the stomach is highly acidic (pH 1-2) so bile is secreted on the chyme to neutralise it as it is very basic. This causes the duodenum to become slightly basic. Also the pancreatic juices have a OPTIMUM pH which is slightly basic so for them to work the bile must make the duodenum slightly basic
46
What is bile?
It is a green coloured liquid that is created by the Liver and stored in the gall bladder. It is highly basic neutralising the chyme and also emulsifies lipids to INCREASE surface area to volume ratio so that the digestive enzyme lipase can digest lipids more efficently
47
What is intestinal juice?
Produced by the wall of the small intestine it contains peptidase which breaks down peptides into amino acids
48
What is the chemical digestive process to break down starch into glucose?
Starch --- salivary amalyse + pancreatic amalyse ---\> Maltose ---\> maltase ---\> glucose
49
What is the chemical digestive process to break down protein into amino acids?
Protein --- stomach pepsin ---\> peptides --- pancreatic trypsin ---\> amino acids
50
What is the chemical digestive process to break down lipids into glycerol + 3 fatty acids?
Lipids --- pancreatic lipase ---\> glycerol + 3 fatty acids (bile also emulsifies the lipids so that the surface area to volume ratio is greatly increase, however it does not digest the lipids FYI)
51
Where is the ilium located?
In the 2nd part (last part) of the small intestine
52
What is the purpose of the ilium?
To absorb digested food into the blood stream
53
What adaptations does the small intestine have to maximise its absorbtion abilities?
- very long, the small intestine has a small diameter but is folded over many times, this means that food takes longer to travel the small intestine and is more likely to be absorbed
- inside of small intestine is lined with villi, they have a very thin cell wall so that food can easily be absorbed, has a blood vessel in it so that food is absorbed into the blood stream easily (also lacteal to absorb glycerol and fatty acids), they greatly increase the surface area of the small intestine, thereby increaseing the rate nutrients can be absorbed
- villi are lined with microvilli, this further increase the surface area of the villi greatly to maximise absorbtion
- when food is being digested blood rushes to the small intestine, this increase the amount of food that can be absorbed as there is more blood to take it, also makes the villi stand up which increase their surface area
- in the duodenum, the pH is 7-8, this is the optimum pH of the pancreatic juice enzymes which allows for the food to be digested at it's fastest rate
- the cell walls of the small intestine are very thin (1 cell thick), this allows food particles to be absorbed through and into the blood stream or lacteal easily increasing the rate which food can be absorbed into the body
54
What is the purpose of the villi?
Greatly increase the surface area of the small intestine so that more food can be absorbed quicker
55
What is the purpose of the microvilli?
Greatly increase the surface area of the villi which further increases the rate of absorbtion of food
56
What nutrients are absorbed by the villi, what vessels take them?
All nutrients are absorbed by the villi, glucose, amino acids, vitamins and mineral are absorbed by the blood vessel, fatty acids and glycerol and absorbed by the lacteal
57
What vessels do digested nutrients get absorbed into, what goes into them, where does it go?
-The blood vessel (carrying glucose, amino acids, vitamins and minerals) goes to the liver via the hepatic portal vein where it is processed into new nutrients, re-directed into the body or stored as fat -the lacteal (carrying fatty acids and glycerol) goes to the lymph vessel which goes into the lymph system
58
Why does food need to be broken down into glucose, amino acids and glycerol + 3 fatty acids?
So that the food molecules can pass through our gut wall into our blood stream and so they can pass through the cell membranes
59
What are the accessory organs?
-Liver -Pancreas -Gall bladder
60
What is the function of the pancreas?
It produces the digestive enzymes: Lipase - breaks lipids down into glycerol + 3 fatty acids Trypsin - breaks peptides down into amino acids Maltase - breaks maltose down into glucose
61
What is the function of the liver?
Performs many function, some of which are: -produces bile, this does 2 things, 1-emulsifies fats so they are soluble and INCREASES their surface area, 2-neutralises the chyme to create optimum pH for enzymes -converts unused glucose into glycogen -produces proteins from amino acids -produces cholestrol -filters the blood of poisons, eg alcohol -stores vitamins A, D, K and B12
62
What is the functino of the gall bladder?
Stores the bile produced by the liver (liver produces about 1 liter of bile per day :O, made from destroyed haemoglobin and cholestrol in the liver FYI)
63
What is the colon?
aka Large intestine, it absorbs water and sodium ions, helps firm up the faeces
64
What are faeces?
Undigested food material, mainly cellulose as most animals (including humans) don't have necessary enzymes to digest cellulose
65
Where are faeces stored?
The rectum (technical name of pooing is defecation FYI)
66
What is the anus?
The lowest most sphincter, controls the release of faeces from the rectum
67
What is the appendix?
It is the humans equivalent of a caecum, however it is poorly developed and has no function, can actually be detrimental (appendicitis)
68
What are the different types of digestive systems?
Herbivores (foregut and hindgut), Carnivore and Omnivore
69
What are the 2 different types of herbivore digestive systems? what are their main differences?
-Hindgut and foregut: -Hindgut have a very large caecum -that ferments cellulose with bacteria -excreted as soft faecal pellets, then re-ingested -Foregut have a very large stomach (~70% of the digestive tract) -multi-chambered stomach, including rumen which houses fermenting bacteria -regurgitates food to mechanically break digest -very long small intestine, increases absorption time
70
What are the main differences between and herbivore's digestive tract (foregut and hindgut) and a carnivore or omnivore digestive tract?
-Herbivore has very long digestive tract as cellulose is hard to digest, carnivores+omnivores don't because meats and berries etc. easier to digest, also don't want meat rotting in their digestive tract -Herbivores have caecum or rumen that houses bacteria, carnivores+omnivores have poorly developed caecum (or appendix) that serves no use -Herbivores have a near neutral acidity stomach (pH 5-7), carnivores+omnivores have a very acidic stomach (pH 1-2) to kill microbes on meat -Herbivores have molars and incisors but carnivores have no molars, have canines and premolars, omnivores have mix of all 4 types -Herbivores have to re-ingest or regurgitate their food, carnivores+omnivores do not -Herbivores don't have stomach pepsin, don't eat protein as main diet+wrong optimum pH for pepsin, carnivores+omnivores have stomach pepsin
71
How is a carnivores digestive system specialised in eating just meat?
-Has a short digestive tract as meat is easy to digest and doesn't want meat rotting, must be quick -stomach very acidic to kill microbes and bacteria and so pepsin is in optimal pH -carnivores teeth are sharp and pointy (canines, incisors and premolars) to rip and slash tissue
72
How is an omnivores digestive system specialised in eating a varied diet?
-Stomach is acidic to kill bacteria on meat, also optimal pH for pepsin -relatively long small intestine (5-7x body length) so that maximal absorption takes place -Large intestine is long to absorb lots of water, also some bacterial fermentation does occur -teeth are varied, can be used to eat a variety of foods such as meats, fruits, cellulose like foods etc
73
How is a Herbivores digestive system specialised in eating a cellulose based diet?
-Ferments cellulose to break down tough cell wall to get at nutrients -Has a large diastema so that it can chew lots of food at once (foregut and hindgut) or so it can have lots of salivary amylase working (foregut) -Relatively to body size long small intestine to maximise absorption
74
List the order of structures that food goes through before it is excreted
Ingested ---\> Mouth --\> Oesophagus ---\> Stomach ---\> Small intestine (duodenum) ---\> small intestine (ileum) ---\> colon ---\> rectum ---\> excreted
75
What do the teeth do to digest food?
-Grinds/slices food up - physical digestion, greatly increase surface area for enzymes to work on
76
What does the tongue do to digest food?
-Moves the food around in the mouth, also forms bolus (ball of chewed up food) -Sense of taste (sweet, sour, bitter, salty)
77
What does the salivary gland do?
-produces saliva that moistens food to make it easier to digest -produces salivary amalyse that begins to break starch down into maltose
78
What does the oesophagus do?
-Transports food from the mouth into the stomach, controls the rate which food goes into stomach through peristalsis
79
What does the stomach do to digest food?
-Physically breaks it down by contracting its muscular walls -Chemically breaks it down by breaking down protein into peptides by the enzyme pepsin -Kills microbes and bacteria on food by high pH -absorbs very small molecules that don't need digesting (ie alcohol, water) -Makes intrinsic factor (needed for absorption of B12 vitamin necessary for production of haemoglobin)
80
What does the duodenum do to digest food?
-It is where chemical digestion occurs -pancreatic juices are mixed with chyme from the stomach -bile emulsifies fats and neutralises the chyme -intestinal juices (peptidase) are produced by gut walls, breaks down peptides into amino acids)
81
What does the ileum do in the digestive tract?
-Is where the digested food molecules glucose, amino acids, glycerol+3 fatty acid and vitamins and mineral are absorbed into the bloodstream by the villi and microvilli
82
What does the pancreas do to digest food?
-Produces pancreatic juice which contains the digestive enzymes trypsin, lipase, maltase and pancreatic amylase which are then mixed with the chyme in the duodenum -mixes it with the chyme by secreting it down the pancreatic duct
83
What does the Liver do to digest food?
produces bile which: -emulsifies fats to increase the surface area to volume ratio so that the digestive enzyme lipase can more efficiently digest lipids\ -neutralises the chime so that the digestive enzymes in pancreatic juice have the optimum pH to digest food
84
What does the gall bladder do?
-It stores the bile that is produced by the liver and then mixes it with the chyme by secreting it down the bile duct
85
What does the large intestine do?
-It absorbs water and sodium ions -this firms up faeces and makes it easier for the waste to be pushed along by peristalsis
86
What does the appendix do in the human body?
-Nothing (it is unused in humans but is a very important feature in herbivores as it ferments cellulose by housing bacteria FYI)
87
What does the rectum do?
It stores faeces
88
What does the anus do?
It controls the release of faeces from the rectum
89
What are enzymes?
-Biological catalyst -A very large protein that breaks large molecules into smaller ones
90
What does the optimum conditions for an enzyme mean?
-It is the conditions, ie temperature and pH that a specific enzyme works most efficiently at (-different enzymes have different optimum conditions, pepsin works best at a pH of 1-2, salivary amylase works best at a pH of 7 -most enzymes have an optimum temperature of 37˚C (body temperature) FYI)
91
What is the lock and key model representing?
It describes how only one type of enzyme can break apart one type of protein
92
What is the process of an enzyme working on a substrate?
1 - Substrate fits into active site on an enzyme 2 - Substrate and enzyme temporarily bond 3 - Enzyme then breaks the bonds holding the substrate together to make it smaller, eg starch broken into glucose
93
What enzyme is present in the mouth and what does it do?
Salivary amylase, breaks starch into maltose
94
What enzyme is present in the stomach and what does it do?
Pepsin, breaks proteins down into peptides
95
What enzymes are present in the duodenum and what doe they do?
Amylase - breaks starch into maltose Trypsin - breaks peptides into amino acids Lipase - breaks lipids into glycerol+3 fatty acids
96
why are digestive organs such as the small intestine long?
-So allow more time for the food to be acted on by enzymes further breaking it down
97
How does and what does physical digestion do to food?
-breaks down food into smaller pieces by teeth, bile and muscle contractions
98
How does and what does chemical digestion do to food?
-breaks down large insoluble molecules into smaller soluble molecules through the use of enzymes
99
Label the body parts
1 - teeth, 2 - epiglottis, 3 - liver, 4 - gall bladder, 5 - bile duct, 6 - colon, 7 - appendix, 8 - salivary glands, 9 - tongue, 10 - oesophagus, 11 - cardiac sphincter, 12 - stomach, 13 - pyloric sphincter, 14 - doudenum, 15 - pancreas, 16 - pancreatic duct, 17 - ileum, 18 - rectum, 19 - anus
100
What is the function of the cardiac sphincter?
-To stop acid in the stomach from flowing back up the oesophagus
101
What is the function of the pyloric sphincter?
To control the rate which chyme leaves the stomach
102
How does the pH in the digestive system change, why?
- pH 6.4-7.4 in the mouth, so that salivary amalyse has OPTIMUM pH, so that teeth don't decay
- pH 1-2 in the stomach, so that pepsin has OPTIMUM pH, to kill microbes and fungi on the food
- pH 7-8 in the duodenum, so that pancreatic juice has OPTIMUM pH, neutralised chyme by bile so not to burn gut wall
103
How does an enzyme work most efficently?
- At it's optimum pH and temperature
- with a high surface area
- with it ownn specific substrate
104
What is the structure of a tooth, what do they do?
- It is made up of a crown and root with enamel, dentine, pulp cavity and cement all making up the tooth, crown is above the jaw bond, root is below
- crown has the enamel on top of it protecting the rest of the tooth from decay
- root anchors the tooth into the jaw bone with cement securing it onto the jaw bone
