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