Gempur Bio Blog!: Quick Revision-Nutrition

..Well..I have to make it fast for all of you...So I wont post the Brief Account and Diagrams anymore because it is time consuming...
..Starting from this chapter onwards, I'm going to publish the FAQ and the possibilities oof the subtopics to be asked....

...and I'm focussing on Paper 2 and Paper 3 since for Paper1 there will be 3-4 questions are definitely asked from each chapters in Biology.....

1. Types of nutrition:

AUTOTROPHS

Organisms that can synthesis complex organic compound from raw simple inorganic substances
using light or chemical energy.
Photosynthesis and Chemosynthesis

PHOTOSYNTHESIS:

A process through which green plants produce organic molecules from carbon dioxide and water
using light as a source of energy

CHEMOSYNTHESIS

A process which include certain type of bacteria ,synthesise organic compound without the help of light.
These organisms obtain energy by oxiding inorganic substances such as hydrogen sulphide and ammonia

HETEROTROPHS

Organisms that cannot synthesis their own nutrients
Holozoic, saprophyte, parasite

HOLOZOIC

The organisms feed by ingesting solid organic matter which is subsequently digested and absorbed into their bodies..One example..

PARASITE

The organism that obtains nutrient by living on or in the body of another living organism , the host...One example..

SAPROPHYTE

The organisms that feed on dead and decaying organic matter. They digest the food externally before the nutrient are absorbed...One example..

WHAT IS ENERGY?

Energy is needed to perform physical activities and to sustain vital functions such as heartbeat, breathing and for maintaining body temperature at 37° C
The energy is generated by the oxidation of molecules obtained from food during cellular respiration.The unit of energy value is joule per gram (Jgˉ' )
Energy value = the amount of heat generated from the combustion of one gram of food
4.2 joules of energy are needed to raise the temperature of 1g of water by 1°C
Three main energy providing organic molecules are lipids, carbohydrates and proteins
The energy value of:
Carbohydrates = 22.2 kJ/g
Proteins =17.2 kJ/g
Lipid =37.6 kJ/g

1. What is meant by Balanced Diet:

defined as a diet which is made up of seven classses of food // list down all the seven
in the right proportion for the need of the body

2. Please remember the ONE major function for each classes of food such as:

Carbohydrate - provide a source of energy

Proteins- provide a source of materials for growth and repair

Fats- Provide a source of energy

Vitamins- To keep/maintain good health

Mineral salts- For healthy teeths, bones and muscles..//any suitable answer

Fibers- To help intestines to function correctly

...and of course WATER...

Factors affecting the daily energy requirement

Daily requirement of energy depends on age, occupation,weight, health and activities.

You should be able to explain by giving FACTS, then EXPLAIN why, with one or two reasons depending on the MArks allocated for the question...
Should Explain:

Need more...................because...........................
Need less what...............because...............

3. Target Groups you should know are as follows:

1. Pregnant woman:

2. Infants and children:

3.Teenagers: Male? Female?

4. Athletes:
Depending on the type of sport they are engaged in..(Response to the question...BUT the FACT must always come with EXPLANATION )

For example : a foot ball player needs high protein food.. to build new tissues and strong muscle.
A badminton player needs athlete rich in proteins vitamins minerals, and carbohydrates... to provides constant energy during training and competition
They also needs calcium, sodium and potassium.. to prevent muscle cramps.

5.Osteoporosis

6. The elderly

7.Vegetarians

8. Children and teenagers:

They needs carbohydrates
to provide extra energy.
They also need a lot of proteins
to build body tissues.
They should take plenty of fruits and vegetables
to provide dietary fibres, minerals and vitamins.

Definition of Malnutrition :
Result from taking an unbalanced diet in which certain nutrient are lacking, in
excess, or in the wrong proportions.

**Has been asked in Essay 2008 ..[8 marks]

...Nutritional effects such as :Kwashiorkor, scurvy, rikets, osteoporosis, diabetis melitus, obesity...Points/Facts to elaborate:

Lacking / excess..will cause...
Symptoms..(at least ONE major symptom)
Treatments/Prevention (At least ONE)

In 2006, Essay Qs related:

6(b) Constipation, night blindness and anaemia are three health problems. State the cause and suggest the ways to overcome these health problems from nutritional aspects. [ 6 marks]

Tips:

take note there are three health problems to discuss.
Each will carry only TWO marks.
Marks given for: stating the cause and suggest the ways to overcome.[1+1 mark]
But you can suggest more than one ways, let the markers choose one best..

..Next...Human Digestive syatem...Must know the Diagram well...how to draw and label...especially Villus: the most asked diagram (may be not 2009)

..and should be able to explain what happen/the event.. at all sites like: Mouth, stomach,duodenum,small intestine (Ileum)...not forgetting colon too..

..all events involve enzymes..should know the names of enzymes and their substract and the produts......

Application Questions:

1 (a) An operation has been conducted on a patient to remove part of his stomach
as it has become cancerous. As a doctor, explain consequences of his situation to his digestion process. [4 marks]

Suggested answer:

F: Production of gastric juice/pepsin/rennin decrease.
P1:Digestion of protein become slow/decrease
P2:Coagulation of protein by rennin decrease.
P3:Unable to provide acidic medium for enzyme reaction//bacteria can not be destroyed.

(F= fact, P=Explanation )

.........As for Digestive System In Ruminants And Rodents...I dont think it will be a question this year because its already being asked for an essay in 2006...

Qs:Explain one similarity and four differences between the alimentary canal of Q and R..[10 marks]

**Q is rabbit, R is cow...

1. Take note on ONE and FOUR...Follow the requirement of the question...Dont give more ....

2.Differences can be written in a form of TABLE.

3.Must know the meaning of alimentary canal...

4. Plan the essay properly..before start answering..

5. You really can score full marks for This type of question if you manage to produce correct facts...

ABSORPTION AND ASSIMILATION OF DIGESTION FOOD

* The parts of the digestive system involved in the absorption of digested food is small intestine
*The adaptive characteristic of the digestive system related to absorption are:

-The epithelial lining is only one cells thick so..............................
-The epithelial cells of projection called microvilli, so this will increase the surface area available for absorption
-Each villus also has a network of blood capillaries and a lymphatic vessel called a lacteal so.......

...Remember!! for every Facts you produce You must tag along the explanation!!!!!

Next prosess is ....

The Assimilation Of Digested Food

Assimilation:
A process of incorporating digested food into our body cells and tissues
so that they can become part of body tissue.
An example is the building of cytoplasm by using amino acids from the digestion of proteins.

Explain how the assimilation process happens in the liver.

-The liver acts as a checkpoint which controls the amount of nutrients released into the blood circulatory system.
-Most of the glucose is converted into glycogen and stored in the liver.

-When the blood sugar level falls and the body needs energy , the stored glycogen is converted back to glucose.

-Glucose is distributed throughout the body by the circulatory system.

-When the glucose molecules reach the cells, they are oxidized to release energy during cellular respiration.

-When the glycogen store in the liver is full, excess glucose is converted into lipids by the liver.

-Like glucose ; amino acids have to pass through the liver before they reach the blood circulatory system.

-The liver synthesizes plasma proteins from amino acids.

-When there is a short supply of glucose and glycogen, the liver converts amino acids to glucose. -Amino acids which enter the cells are used for the synthesis of new protoplasm

-and the repair of damaged tissues.

FORMATION OF FAECES AND DEFAECATION...has been asked in 2008 Essay [4 marks]

EVALUATING EATING HABITS.
Health Problems Related To Eating Habits...