Our topic for today in biology is “Anabolism And Feeding In Living Organisms”, so let not waste time.
Anabolism : is the synthesis, by living things, of complex compounds from simple substances.
Living things require food I.e carbohydrates, proteins, minerals salts, vitamins, fat and oil (lipids) and water, all this are needed by living things to grow, repair worn out tissues, produce energy for life activities and for production of new protoplasm.top↑
But no withstanding,
Feeding : is the process by which an organism obtains the nourishment which provides it with the energy for its life activities as well as materials needed for growth, development and maintenance of good health.top↑
There are two main types of feeding or nutrition in organisms, which are, autotrophic and heterotrophic nutrition or feeding
First let start with autotropic nutrition.
Autotropic Nutrition Or Feeding : is the type of feeding in which the organism makes its own complex organic foods molecules from simple inorganic substances.
Autotropic organism ( autotrophs) are also refer to as self feeding organism and they are of two forms, some are photosynthetic while some are chemosynthetic.top↑
Photosynthetic autotrophs : from the word “photo” which means light in physics and besides photosynthetic from the word photosynthesis. Photosynthetic autotrophs are organisms which use chlorophyll to absorb energy from sunlight with carbon dioxide and water as raw materials to produce mainly starch (glucose) which are later store as glycogen. top↑
From glucose, photosynthetic organism can synthesise starch and other carbohydrates, proteins, minerals salts, lipids that is, fat and oil, vitamins and other food compounds. Examples of this autotrophs are bacteria that contains chlorophyll, blue-green algae, and green plants.
Chemosynthetic autotrophs : are autotrophs that synthesis complex organic food molecules from simple inorganic substances by using energy obtained from exergonic inorganic oxidation reactions. Examples of this chemosynthetic autotrophs are;
1] Nitrobacter : a nitrifying bacterium that converts nitrites to nitrates. This reaction releases energy used for synthesis of food.top↑
2] Nitrosomonas : a nitrifying bacterium that converts ammonium compounds to nitrites. This reactions releases energy which the bacterium uses for making food.
3] A group of chemosynthetic sulphur bacteria oxidize sulphur to tetraoxosulphate (vi) acid
Heterotrophic Nutrition Or Feeding
Animals and non-green plants cannot produce their own food but depends on plants or other animals for their food.
E.g Man, we all depend on either plants or animal to feed on, e.g goat, cabbage lettuce, etc.top↑
brief : Organisms that obtain complex food molecules from plants or animals are called heterotrophic autotrophs. This organisms take in the complex food materials and digested it, that is, converting the complex food materials into simple food materials such as glycerol, amino acids, fatty acids and simple sugar.top↑
This converted simple food materials are then absorbed and utilized by the body to provide energy or to synthesize new protoplasm for growth and repair of worn-out tissues and cells.
Types Of Heterotrophic Nutrition Or Feeding
1] Holozoic : is the type of nutrition or feeding exhibit by animals with cavities, e.g Man, amoeba, etc.
2] Parasitic : Is a feeding relationship between a parasite and host where the parasite enjoys while the host suffers, e.g tapeworm in intestine of a man, mistletoes on a cocoa tree or colanut tree. Parasitic feeding is a negative feeding because one is feeding on one.top↑
3] Symbiosis Or Mutualism : this is an association (not feeding) between two living organisms of different kinds where each organism benefit from the relationship, e.g bacteria in the root nodules of a leguminous plant, Algae and fungi on lichen and bacteria in the intestine of ruminant animal.
4] Saprophitic : is the feeding of an living organisms on dead and decay organic matter, e.g mucor on a stake bread and mushroom on a dead wood.top↑
5] Commesalism : is a relationship (not feeding) between two organisms in which one of the organism enjoy while the other organisms does not benefit nor suffer from the relationship, e.g remora and shark.
The remora dodge or lain beside the shark in order to scare the predators away. Is like trying to avoid bullies at school by rolling with some other niggas.
6] Epiphytic : is the feeding relationship between two plants and which the host does not benefit or suffers e.g when a bird build a nest on top of a tree, it is possible that in that nest a plant may started growing, that plant is called epiphyt and it obtains its nutrients from the nest components not from the host (the tree).top↑
7] Co-operation : is the feeding relationship between two organisms, in which both benefits from the relationship but each organism can live an independent life without the other, e.g cattle and cattle-eaglet.
8] Carnivorous Or Insectivorous : This are plant that feed on insects, e.g pitcher, drasera, venus plant, sundrew and bladder wort. This is a negative feeding relationship because one is feeding on one.
9] Predation : this is a feeding relationship between predators and preys, e.g lion as the predator and antelope as the prey. Predation is a negative feeding relationship because one organism is feeding on the other.top↑
Methods Of Collecting And Taking In Food By Heterotrophic Organism
1] Filter Feeding : A filter feeder organism strains small particles of food from water in which it lives, e.g fish, herring as an example of fish, herring takes in water through the mouth and passes it out through the gills slits.top↑
brief : Gills is used for breathing and also for feeding in fish.
As the water passes through the gills slits (a.k.a gill rackers), the gill rackers strain out particles of food from the water and the organism feeds on the particles, other examples are whales, some whales are filter feeders.
2] Sucking Method Of Feeding : some organism suck liquid food, e.g mosquitoes which sucks vertebrates blood e.g man and aphids which suck the juice of plants.top↑
Brief : The reason why mosquitoes suck blood is for its eggs to survive not because of feeding, the egg needs the warmth (temperature) of the blood to survive. I.e it is a female mosquitoes that bites.
So that means whenever you killed a mosquito and you thinks you just killed only one mosquitoes, nope you kill more than that, so henceforth stop killing mosquitoes and let them peacefully suck you blood.top↑
3] Chewing And Biting Method Of Feeding : Mostly other living organisms chew and bite their food, e.g man, goat, ram, locusts, rat, etc.
Those are the taking in methods of food by heterotrophic animals, also read nutrition in microscopic organisms : paramecium
Now let look at role of enzymes in digestion
Role Of Enzymes In Digestion
First what is an enzyme?
An enzyme is an organic catalyst produced in living tissues, which speed up and controls the rate of metabolic activities and reactions.top↑
What Is Digestion?
Digestion : is the breaking down of complex food molecules to simpler molecules in order to be easily absorbed by the organism.
Food substance eaten by animals are usually complex food substances, the enzymes split the bonds in complex molecules, this splitting down of complex molecules changes starch to glucose, fatty acids and proteins into amino acids, and lipids to glycerol.
Let stop here for today till next class.
Next Topic : Cellular Or Tissue Respiration
Feel free to ask our tutors any question via the comment box or use our ask question page and we will be happy to answer your question and take the session again if necessary, your comment notifications is a motivation to us, so don’t forget to write something.top↑