2.4 nutrition Flashcards
definition of nutrition
obtaining nutrients to provide energy to maintain life functions, and matter to create and maintain structure
2 types of nutriton
autotrophs (producers)
heterotrophs
examples of autotrophs
plants/phytoplankta
examples of heterotrophs
paramecium/animals
what do autotrophs do
use simple inorganic materials such as water and carbon dioxide to manufacture energy. containing complex organic compounds
what do heterotrophs do
depend on autotrophs for their food supply. they consume complex organic food material, which must be broken down before its used
what do autotrophs provide
food for all other forms of life
photosynthesis in terms of food
light is the source of energy for the production of food.
2 types of bacteria
photosynthetic
chemosynthesis
photosynthetic bacteria…
use a pigment called bacteriochlorophyll (blue/purple) which needs light to photosyntheise
chemosynthesis bacteria….
can synthesise organic compunds from inorganic compounds in the absence of light
what are the organisms who aren’t dependent on photosynthesis reliant on
chemosynthesis
process of chemosynthesis
process where they use chemicals in hydrothermal vents to produce energy
properties of heterotrophic nutrition
- connot make their own organic food
- must consume organic compound made by autotrophs
- known as consumerz
4 types of heterotrophic nutrition
-holozoic feeders
-saprophytes
-parasites
-mutualism
explain holozoic feeders…..
-include nearly all animals
-they take food into their bodies and break it down (digestion)
- most have specialised digestive systems
- digestive materials is then absorbed into the body tissue
herbivores
solely plant materials
carnivores
feed on other animals
detrivores
animals that feed on dead/decaying material
explain saprophytes
-feed on decaying matter
-don’t have a specialised digestive system
- include some bacteria/ALL fungi
-secrete enzymes
-food source is absorbed by diffusion across the cell membrane
- important in global ecosystems
where to saprophytes secrete enzymes
happens at the tip of the structure, the hypha
why are saprophytes important in global ecosystems
play a major part in decomposing dead plant materials and recycling nutrient (nitrogen)
explain parasites…..
-organisms that feed on/in other living organisms. host always suffers harm to some degree
-highly specialised and adaptive
example of parasites
tapeworm,malarial parasite
explain mutualism
or symbosis, involves a close association between members of two separate species. both benefit from the relationship
example of mutualism
digestion of cellulose by microorganisms in the gut of a herbivore
Example of unicellular organisms
Amoeba
Explain the digestion in unicellular organisms
-large SA to volume ratio
- May take in food by diffusion, facilitated diffusion, active transport
- May take in food by endocytosis, enzymes digest food in bachelors
- Exocytosis removes indigestion remains
Explain multicellular (with single body opening) organisms
- cylindrical with tentacles surroundings its mouth
-extracellular digestion by enzymes
-products of digestion absorbed and remains egested in the mouth
Explain the digestive system of a shark
-short thick intestine pathway (high protein diet)
- Wide oesophagus
- large liver
Digestive system of salamender
Long small stomach
thin oesophagus
Digestive system of a liver
Bumpy intestine
Large curved stomach
Digestive system of a pigeon
Large crop (storing foods on long journeys)
Long intestine pathway
Gizzard (to break down food, they don’t have teeth)
Function of serosa
Protection, reduced friction between but and other organs
Properties of serosa
Outermost layer
Tough connective tissue (fibrous tissue, collagen)
What are the four layers of the gut wall
-serosa
-muscle
-submucosa
-mucosa
Properties of muscle
Inner circular muscle and outer longitudinal muscle that works together
Function of muscle layer
Peristaltic
Behind ball of food, circular contract and longitudinal relax
Properties of the submucosa layer
Connective tissue
Blood and lymph vessels, nerves
Function of the submucosa layer
vessels remove absorbed products of digestion. Nerves co-ordinate peristalsis
Properties of mucosa layer
Outermost layer
Function of mucosa layer
Epithelium secretes mucus. In some regions it secretes digestive juices and in others it absorbs digested food
What is physical digestion
Cutting and crushing by teeth
Mixed with saliva and mucus to soften the food and lubricate it
What is chemical digestion
In the mouth saliva contains saliva contains amylase to digest starch to maltose
Role of the oesophagus
Carried food to the stomach
What do oesophagus contain
Goblet cells
Circular and longitudinal muscle
What do goblet cells do
Produce mucus to lubricate the food
(found in mucosa)
What do circular/longitudinal muscles do
Allow peristalsis
What is peristalsis
Wave like motion pushing food down through the gut
What are found in the mucosa
Contains gastric pits
What do gastric pits contain
Oxyntic cells
Zymogen cells
Goblet cells
What do oxyntic cells contain
Produce HCL
What do Zymogen cells produce
Produce pepsinogen
What do goblet cells produce
Produce mucus
How is pepsinogen activated
By HCL to make pepsin
What does pepsin do
Breaks peptide bonds between amino acids in a polypeptide chain
What is the function of the stomach
protein is digested, breaks large polypeptides into smaller polypeptides
Enzymes involved in the stomach
Endopeptidase
(Pepsinogen)
Special features of the stomach
- sphincter muscles,
- Wall muscles contract rhythmically (circular and longitudinal)
- Gastric pits are glands in the mucosa
first part of the small intestine called
duodenum
role of the first section of the small intestine
-receives secretion from the liver and pancreas
-has bile from liver (stored in the gall bladder) bile salts emulsify lipids to increase SA
-aids lipase digestion
what are pancreatic juices secreted by
islet cells (glands in pancreas)
what does the duodenum contain
enzymes
3 types of enzymes in the duodenum
trypsin
exopeptidase
amylase/lipase
what is trypsin an example of
endopeptidase
how is trypsin made
trypsinogen turned to trypsin by enterokinase
what do exopeptidase do
hydrolyse peptide bonds on the end of peptides, from the free amino end or the free carboxyl end
what does the duodenum also contain
sodium hydrogen carbonate (alkaline to neutralise stomach acid)
what is the Brunner’s gland
where alkaline secretions released
second part of the small intestine
ileum
2 roles of the ileum
digestion and absorption
what do the epithelial cells at tips of villi do
-produce endopeptidase and exopeptidase (dipeptides to amino acids)
- digest disaccharides into monosaccharides
what is maltose broken down into
2 alpha glucose by maltase
what is sucrose broken down into
glucose and fructose by sucrase
what is lactose broken down into
glucose and galactose by lactase
second role of ileum
absorption
what does the ileum contain
villi with microscopic projections called microvilli
what do the microvilli do
give an even larger surface area for absorption (by diffusion, FD and AT)
how do amino acids go from the lumen to epithelial cells
AT with sodium ions, uses ATP
(CARRIER PROTEINS)
how do aminon acids get from epithelial cells into the capillary
FD- channel/carrier protein. then go to the liver via the hepatic portal vein
how is glucose transported from the lumen to epithelial cells
CT- with sodium ions
how is glucose transported from the epithelium cells into capillary
Sodium ions active tranport
glucose FD (some AT)
they will go by FD until equilibrium, AT to get the rest of the glucose into the blood
how are fatty acids and glycerol transported from the lumen to epithelial cells
Difusion, reform to become triglycerides again
how do fatty acids and glycerol go from epithelial cells into capillary
go into lacteals instead and are passed to the lymphatic system
what happens to the molecules once they are digested
glucose and amino acids are transported via the hepatic portal vein to the liver
fatty acids and glycerol diffuse into the epithelial cells, return to triglycerides. go to the lacteal and are carried via the lymphatic system
what is the large intestine made up
caecum, appendix, colon and rectum
what happens in the large intestine
-undigested food, mucus, bacteria and dead cells pass into the cell
- does not have villi, not as many as the ileum
- where water and mineral absorption happens
vitamin K and colic acids are secreted by mutualistic microbes living there
what is folic acid important for
the nervous system
dentation of a carnivore
- incisors
- canine
-premolars
-carnassials
-jaw (mandible)
properties of incisors
carnivore
sharp
job of incisors
carnivores
tear muscle from bone
properties of canines
carnivore
large, curved, pointed
job of canines
carnivores
to tackle prey
properties of premolars and molars
carnivores
sharp points (cusps)
job of premolars and molars
carnivores
to cut and crush
properties of carnassial
carnivores
specialised cheek teeth that act like scissor blades
job of carnassial
carnivores
takin muscle of bones
explain the jaw of a carnivore
lower jaw moves vertically and can open widely. jaw muscles are powerful. protrusions in skull for muscles to attach to bone
dentation of herbivores
-incisors
- canines
-dental pad
-diastema
-premolars
-molars
-jaw
properties of incisors
herbivores
bottom jaw only
role of incisors
herbivores
slices through plants
properties of canines
herbivores
indistinguishable from incisors
role of canines in herbivores
slices through plants
properties of dental pad
herbivore
leathery pad on the upper jaw
job of dental pad
herbivores
where food gets pulled across for slicing
properties of diastema
herbivores
gaps between front teeth and premolars where tongue and cheek operate
properties of premolars
herbivores
side teeth
role of premolars
herbivores
chewing plants
properties of molar
herbivore
they interlock. grinding action occurs. continue to grow
describe the jaw
Lowe jaw muove side to side
no strong muscles are needed
what is a ruminant
a cud-chewing herbivore that has mutualistic microbes in the rumen
what is a rumen
part of stomach
what does bacteria get out of the mutualistic relationship
food and a place to live
what does their diet mainly consist of
grass (cellulose)
what do animals rely on to break down cellulose
rely on mutualistic microbes living in their gut to secrete enzymes e.g fungi, bacteria and protocista which live in a chamber called the rumen
what are the 4 stomachs of a cow
rumen
reticulam
omasum
abomasum
explain the rumen
what does it contain
contain microbes that digest cellulose
cellulose breaks down into glucose
explain the reticulum
fermented grass become cud and goes back to the mouth
explain the omasum
from the mouth it goes to the omasum, where water is reabsorbed
explain the abomasum
true stomach
protein is digested by pepsin
what are parasites
-highly specialised organism that live in/other organisms (host) and so obtain nourishment at the expense of host organisms
what do parasites gain from other organisms
nutrition-which is absorbed from the hosts tissues and fluids or the intestine
2 types of parasites
ECTOparasites
ENDOparasites
what are ectoparasites
live on the outside of the body
head louse
what are endoparasites
live inside the host
e.g roundworms, tapeworms and blood flukes
what problems do tapeworms face
-digestive juices
-peristalsis
-pH of gut
- host immune system
- death the host
structural modifications to aid survival of a tapeworm
-suckers and a double row of curved hooks attaching to duodenum wall (for attachment)
-a thick body covering (cuticle) to protect from immune system
- production of inhibitory enzymes on the surface of the body segments (protection from digestion)
- tapeworm has flattened body to increase SA to volume ratio and is can absorptionb food (nourishment)
reproductive strategies of the tapeworm
1) hermaphrodite - each body segment have male and female gametes. the gut cannot accommodate 2 tape worms (asexual reproduction
2) large number of eggs are produced
mature segments can contain up to 40,000 eggs to increase chance of survival
