Biology

All animals take in oxygen for oxidation of organic compounds to provide energy for cellular activities. The carbon (IV) oxide produced as a by-product is harmful to cells and has to be constantly removed from the body. Most animals have structures that are adapted for taking in oxygen and for removal of carbon (IV) oxide […]

Gaseous exchange takes place by diffusion. The structure of the leaf is adapted for gaseous exchange by having intercellular spaces that are filled. These are many and large in the spongy mesophyll. When stomata are open, carbon(IV)oxide from the atmosphere diffuses into the substomatal air chambers. From here, it moves into the intercellular space in

The water lily, Salvia and Wolfia whose stems remain in water are permeable to air and water. Oxygen dissolved in the water diffuses through the stem into the cells and carbon (IV) oxide diffuses out into the water. Gaseous Exchange in Roots Terrestrial Plants Gaseous exchange occurs in the root hair of young terrestrial plants.

Living organisms require energy to perform cellular activities. The energy comes from breakdown of food in respiration. Carbon (IV) oxide is a by-product of respiration and its accumulation in cells is harmful which has to be removed. Most organisms use oxygen for respiration which is obtained from the environment. Photosynthetic cells of green plants use

Oxygen is required by plants for the production of energy for cellular activities. Carbon (IV) oxide is required as a raw material for the synthesis of complex organic substances. Oxygen and carbon (IV) oxide are obtained from the atmosphere in the case of terrestrial plants and from the surrounding water in the case of aquatic

Making of beer and wines. Ethanol in beer comes from fermentation of sugar (maltose) in germinating barley seeds. Sugar in fruits is broken down anaerobically to produce ethanol in wines. In the dairy industry, bacterial fermentation occurs in the production of several dairy products such as cheese, butter and yoghurt. In production of organic acids

Carbohydrate, mainly glucose is the main substrate inside cells. Lipids i.e. fatty acids and glycerol are also used. Fatty acids are used when the carbohydrates are exhausted. A molecule of lipid yields much more energy than a molecule of glucose. Proteins are not normally used for respiration. However during starvation they are hydrolysed to amino

COMPARISON BETWEEN ENERGY OUTPUT IN AEROBIC AND ANAEROBIC RESPIRATION Aerobic respiration results in the formation of simple inorganic molecules, water and carbon (Iv) oxide as the by¬products. These cannot be broken down further. A lot of energy is produced. When a molecule of glucose is broken down in the presence of oxygen, 2880 KJ of

BIOLOGY PRACTICAL ACTIVITIES To Show the Gas Produced When the Food is burned A little food substance e.g., maize flour or meat is placed inside a boiling tube. The boiling tube is stoppered using a rubber bung connected to a delivery tube inserted into a test-tube with limewater. The food is heated strongly to bum.

Respiration is the process by which energy is liberated from organic compounds such as glucose. It is one of the most important characteristics of living organisms. Energy is expended (used) whenever an organism exhibits characteristics of life, such as feeding, excretion and movement. Respiration occurs all the time and if it stops, cellular activities are