Biology Master

Biology

INTRODUCTION TO TRANSPORTATION

INTRODUCTION TO TRANSPORTATION
Transport is the movement of substances within an organism.
All living cells require oxygen and food for various metabolic processes.
These substances must be transported to the cells.
Metabolic processes in the cells produce excretory products which should be eliminated before they accumulate.
The excretory products should be transported to sites of excretion.
Organisms like amoeba are unicellular.
They have a large surface area to volume ratio.
The body is in contact with the environment.
Diffusion is adequate to transport substances across the cell membrane and within the organism.
Large multi-cellular organisms have complex structure where cells are far from each other hence diffusion alone cannot meet the demand for supply and removal of substances.
Therefore an elaborate transport system is necessary.

Biology

BIOLOGY PRACTICAL ACTIVITIES

BIOLOGY PRACTICAL ACTIVITIES
Experiments to show that Carbon (IV) Oxide is necessary for Photosynthesis
Experiment to Show Effect of Light on Photosynthesis
Experiment to Show the Effect of Chlorophyll on Photosynthesis
Experiment to Observe Stomata Distribution in Different Leaves
Test for Reducing Sugar
Test for non-reducing sugar
Test for Lipids;

Biology

FACTORS DETERMINING ENERGY REQUIREMENTS IN HUMANS

FACTORS DETERMINING ENERGY REQUIREMENTS IN HUMANS
Age: Infants, for instance, need a greater proportion of protein than adults
Sex: males generally require more carbohydrates than females
The requirements of specific nutrients for females depends on the stage of development in the life cycle
Adolescent girls require more iron in their diet; expectant and nursing mothers require a lot of proteins and mineral salts
State of Health: A sick individual requires more of certain nutrients eg proteins, than a healthy one
Occupation: An office worker needs fewer nutrients than a manual worker

Biology

IMPORTANCE OF VITAMINS, MINERAL SALTS, ROUGHAGE AND WATER IN HUMAN NUTRITION VITAMINS

These are organic compounds that are essential for proper growth, development and functioning of the body
Vitamins are required in very small quantities.
They are not stored and must be included in the diet. Vitamins Band C are soluble in water, the rest are soluble in fat. Various vitamins are used in different ways

Mineral Salts

Mineral ions are needed in the human body
Some are needed in small amounts while others are needed in very small amounts (trace)
All are vital to human health
Nevertheless, their absence results in noticeable mulfunction of the body processes

Biology

DIGESTIVE SYSTEM AND DIGESTION IN HUMANS

DIGESTIVE SYSTEM AND DIGESTION IN HUMANS.
Organs that are involved with feeding in humans constitute the digestive system.

Digestive System and Associated Glands

Human digestive system starts at the mouth and ends at the anus
This is the alimentary canal
Digestion takes place inside the lumen of the alimentary canal
The epithelial wall that faces the lumen has mucus glands (goblet cells)
These secrete mucus that lubricate food and prevent the wall from being digested by digestive enzymes
Present at specific regions are glands that secrete digestive enzymes
The liver and pancreas are organs that are closely associated with the alimentary canal
Their secretions get into the lumen and assist in digestions

Biology

COMMON DENTAL DISEASES

COMMON DENTAL DISEASES

Dental Carries

Dental carries are the holes or cavities that are formed as acid corrodes enamel and eventually the dentine
Dental Carries

Dental carries are the holes or cavities that are formed as acid corrodes enamel and eventually the dentine

Causes

This is caused by bacteria acting on the food left between teeth and on the cusp
Acids are formed that eventually corrode the enamel
The pulp cavity is eventually reached
A lot of pain is experienced then
The bacteria then infect the pulp cavity and the whole tooth decays

This is caused by bacteria acting on the food left between teeth and on the cusp
Acids are formed that eventually corrode the enamel
The pulp cavity is eventually reached
A lot of pain is experienced then
The bacteria then infect the pulp cavity and the whole tooth decays

Biology

ENZYMES

Enzymes are biological catalysts that increase the rate of chemical reaction in the body
They are all produced inside cells
Some are intracellular and they catalyse reactions within the cells
Others are extracellular and are secreted out of the cells where they work e.g. digestive enzymes

Properties of Enzymes

Enzymes are protein in nature
Enzymes are specific to the type of reaction they catalyse
This is referred to as substrate specificity
Enzymes work in very small amounts
They remain unchanged after the reaction
They catalyse reversible reactions
They work very fast (high turnover numbers) e.g. the enzyme catalase works on 600 thousand molecules of hydrogen peroxide in one second

Biology

PROTEINS

Proteins are the most abundant organic compounds in cells and constitute 50% of total dry weight
Proteins are compounds which are made up of carbon, hydrogen, nitrogen, oxygen and sometimes sulphur and phosphorus
The structural units of proteins are amino acids
The nature of a protein is determined by the types of amino acids it is made of
There are about 20 common amino acids that make up proteins