Differences between some important terms

Osmotic pressure (π)

Osmotic potential (ψ)

1. It refers to the pressure required to stop the movement of water into a solution through the membrane.

1. Since there is no actual pressure exerted by a solution, it is only the potential to result into pressure when placed in an osmometer, scientists prefer to use the term osmotic potential instead of osmotic

2. It is given a positive sign. It is represented by the greek letter π (pie)

2. It is equivalent to osmotic pressure but is given negative sign. It is represented

by the Greek letter ψ, (psi). So ψ = – π

Osmotic potential (ψ_s)

Matric potential (ψ_m)

1. It is also known as osmotic pressure.

1. It is also known as imbibition pressure.

2. It is the potential pressure required to stop the movement of water into a solution.

2. It results from adhesion of water to cell wall or cytoplasmic matrix of dry seeds. It is due to adsorption of water. Adsorption refers to the movement of water to the surface of dry matter like seeds.

Diffusion

Osmosis

1. It is the random and spontaneous movement of solute or gas molecules.

1. It is the passage of solvent molecules.

2 It is the movement of ions or molecules from a region of high concentration to a of their low concentration. It occurs from a concentrated to a dilute medium.

2. It is the movement of solvent molecules (generally water) from their high concentration to low concentration. i.e. from a dilute to a concentrated solution.

3. This can occur as long as there are no barriers for the movement of solute or gas molecules i.e., the membrane has to be permeable.

3. It is through a differentially permeable membrane (selectively permeable)

4. Ex—Diffusion of 0₂ and C0₂ across the lung membrane (in case of gases the term partial pressure is used).

4. Example: Absorption and secretions across the membrane and transport of water by the plant cells.

Autotrophic nutrition

Heterotrophic nutrition

1. Refers to ‘self nutrition’. Organisms make their food from simple raw materials.

1. Refers to nutrition ‘from others’. Organisms cannot make their own food and derive nutrition from other.

2 Shown by green plants which are also called as producers.

2. Shown by nongreen plants, fungi, bacteria and all animals. Also called as consumers.

3. Autotrophic nutrition is by photosynthesis, a process by which green plants synthesise their food.

3. Heterotrophic nutrition could be saprophytic, parasitic, symbiotic or insectivorous.

Saprophytic nutrition

Parasitic nutrition

1. Organisms feed on dead and decaying animals and plant material (organic matter)

1. Organism called parasite lives in or on other living organism and derives nourishment from it.

2. Saprophytes first break complex organic matter Into simple molecules and then absorb them into their body.

2. Parasites absorb their food from the host.

3. Examples : Fungi like bread mould, mushroom and a number of bacteria

3. Example: Cuscuta (a plant).

Active absorption

Passive absorption

1. Absorption of mineral ions takes place against the concentration gradient.

1. Absorption of mineral ions take place only down the concentration gradient (from high conc. to low conc.).

2. Energy from ATP is required.

2. Does not require energy.

3. It is a rapid process.

3. It is a slow process.

4. Brings about selective uptake of minerals.

4. Usually involves random uptake of minerals.

Light Reaction

Dark Reaction

Location

Takes place in the thylakoids the membrane system of chloroplasts.

Takes place in the stroma region of chloroplasts.

Light requirement

Light is essential.

Does not require light.

Net reaction

Light energy is converted into chemical energy. ATP and NADPH₂ are produced.

No sugar formation.

ATP and NADPH₂ are utilised for the fixation of carbon dioxide.

Sugar formation takes place.

Name of reaction

Hill’s reaction.

Calvin cycle

Overall equation

2H₂0+2NADP +4ADP → 0₂+2NADPH₂+4ATP

6C0₂+6H₂0 + 18 ATP + 12 NADPH₂ → C₆H₁₂O₆ + 12H₂O + 18ADP + 12NADP

Photorespiration

Respiration

1. Occurs in the presence of light only.

1. Occurs all the time irrespective of light.

2. Involves chloroplasts, peroxisomes and mitochondria.

2. Takes place in mitochondria of the cells.

3. Takes place jn green plants only.

3. Takes place in all the living cells.

4. Results in wasteful loss of NADPH₂ and ATP.

4. Results in release of energy in the form of ATP and NADPH₂.

5. Not essential and decreases the yield of C₃ plants.

5. Essential for all the cells.

Transpiration

Translocation

1. It is evaporation of water from the surface of leaves.

1. It is transportation of food made by leaves to different parts of the plant

2. It results in upward movement of water in xylem vessels.

2. It occurs in various directions in the plants. It takes place in the phloem tissue.

Cellular Respiration

Combustion

1. It is a biochemical process.

1. It is a physio-chemical process.

2. The chemical energy is released gradually and in a controlled form.

2. There is a sudden burst of huge energy at one time.

3. The temperature remains between 35—40⁰C.

3. The temperature rises considerably.

4. The metabolic pathways need enzymes at every step.

4. It does not need enzymes.

5. The energy released is stored in ATP molecules and a very small amount is lost as heat.

5. Major part of energy is released as heat.

6. It does not involve emission of light.

6. Light may be emitted.

Aerobic respiration

Anaerobic respiration

1. Food oxidized in the presence of oxygen.

1. Food is oxidized in the absence of oxygen.

2. Complete oxidation of glucose Into CO₂ and H₂O.

2. Incomplete oxidation of glucose into lactic acid or ethyl alcohol.

3. C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O

3. C₆H₁₂O₆ → 6C₃H₆O₃ + Energy

C₆H₁₂O₆ → 2C₂H₅OH +CO₂+ Energy

4. Occurs in cytoplasm and mitochondria.

3. Occurs in cytoplasm only

5. 38 ATP molecules are released.

4. Only 2 ATP molecules are released.

6. Occurs in most animals and all higher organisms.

5. Occurs in organisms like yeast and bacteria in higher organisms it occurs in parasites like tapeworm,

Alcoholic fermentation

Lactic acid fermentation

1. Pyruvic acid is broken down to ethanol and carbon dioxide.

1. Pyruvic acid is broken down to lactic acid.

2. Overall equation is:

C₆H₁₂O₆ → 2C₂H₅OH+2CO₂ +2ATP

2. Overall equation is:

C₆H₁₂O₆ → 2CH₃CHOHCOOH+2ATP

3. C0₂ is released.

3. C0₂ is not released.

4. Occurs in yeast, preparation of beers and wines.

4. Occurs in micro-organism, and jn striated muscles of higher animals (during heavy exercise).

Intracellular digestion

Extracellular digestion

(in holozoic nutrition)

1. Food is digested within a cell.

1. Food is digested outside the cells in a specialised duct called alimentary canal.

2. Digested food diffuses out into the cytoplasm directly.

2. Digested food is absorbed by the cells or blood capillaries.

3. Form of digestion found in lower organisms like Amoeba.

3. Form of digestion found in higher multi- cellular organisms. The intracellular digestion is restricted to lysosomes or macrophages only.

Pepsin

Trypsin

1. Secreted in stomach.

1. Secreted in duodenum.

2. Needs an acidic pH (1-2) for optimum activity.

2. Needs an alkaline pH (7.5-8.5) for optimum activity.

3. The inactive form, pepsinogen is activated by HCI.

3. The inactivated form, trypsinogen is activated by enterokinase.

4. Pepsin does not activate any other enzyme.

4. Trypsin activates other pancreatic enzymes.

Passive Absorption

Active Absorption

1. Nutrients are absorbed along the concentration gradient, from high concentration to low concentration.

1. Nutrients are absorbed against the concentration gradient i.e from low concentration to high concentration.

2. It is a very slow process.

2. It is an active, and a rapid process.

3. Energy is not utilised.

3. Energy is required.

4. Complete absorption of nutrients does not take place.

4. Complete absorption of nutrients takes place.

5. It does not involve other carrier molecules (except in facilitated diffusion).

5. It always requires carrier molecules.

Essential Amino acids

Non-essential Amino acids

1. Cannot be synthesised by the body.

1. Can synthesised by the body.

2. Need to be supplied with food.

2. May or may not be supplied with food.

3. Eight in namely threonine, tryptophan, valine, leucine, isoleucine, lysine and phenylalanine. Arginine is essential for infants only.

3. Twelve in number. Glycine, alanine, serine, cysteine, tyrosine, proline, aspartic acid, glutamic acid, histidine, asparginine.

Essential fatty acids

non-essential fatty acids

1. They cannot be synthesised in the body.

1. They can be synthesised by the body.

2. They must be supplied in the food. e.g. Linoleic, Linolenic and arachidonic acids

2. They may or may not be supplied in the food. e.g. Palmitic acid, stearic acid etc.

Water soluble vitamins

1. Dissolve in water.

1. Do not dissolve in water and instead dissolve in fat solvents like chloroform.

2. Present in certain vegetables and fruits.

2. Present in animal and vegetable fats.

3 Vitamin B-complex (B₁, B₂, B₆, B₅, B₁₂) folic acid and vitamin C.

3. Vitamins A, D, E and K.

Phytosynthesis

Aerobic Respiration

1. It is an anabolic process,

6CO₂ + 12H₂O →C₆H₁₂O₆ + 6O₂ + 6H₂O

1. It is an catabolic process,

C₆H₁₂O₆ + 6O₂ →6CO₂ + 6H₂O + Energy

2. CO₂ and H₂O are used up for synthesizing carbohydrate molecules.

2. CO₂ and H₂O are released during break down of carbohydrate molecules.

3. CO₂ is taken in and O₂ is given out.

3. O₂ is taken in and CO₂ is given out.

4. It takes place only in the presence of light.

4. It takes place continuously through out the life in all the cells.

5. It takes place in chloroplasts.

5. It takes place in mitochondira.

6. Energy in the form of light is required. Energy is accumulated and stored in carbohydrates.

6. Energy in the form of ATP molecules is released.

7. It results in an increase in dry mass.

7. It results in an decrease in dry mass.

SA node

AV node

1. Originates the heart beat and so is called the pacemaker.

1. Cannot originate the heart beat and is not a pacemaker.

2. Spreads the impulse to both the atria.

2. Passes the impulse to AV bundles, for the contraction of ventricles.

3. Present at the entrance of superior vena cava in the right atrium.

3. Present close to interatrial septum near the right AV aperture.

4. Does not pick up the impulse from anywhere, it itself initiates the cardiac impulse.

4. Picks up the impulse generated by SA node.

Atrial Systole

Ventricular Systole

1. Contraction of’ atria and relaxation of ventricles.

1. Contraction of ventricles and relaxation of atria.

2. Bicuspid and tricuspid valves are open.

2. Bicuspid and tricuspid valves are closed.

3. Closing of great vein roots and no sound is produced. AV valves are open.

3. Closing of AV valves produces the heart sound lubb.

4. Blood is poured into ventricles.

4. Blood is pumped out in great arteries.

5. Lasts for about 0.15 seconds.

5. Last for about 0.25 seconds.

Mitral valve

Semilunar valve

1. Also referred as bicuspid valve since it consists of 2 flaps.

1. Valves consist of 3 flaps.

2. Guards the opening of left atrio-ventricular aperture.

2. Present at the base of pulmonary artery and aorta and at regular intervals in veins.

3. Allows the blood to move from left atrium

3. In the heart they allow the blood to flow from ventricles to great arteries and in the

veins allow the blood to flow towards the heart.

4. Valves are attached to chordae tendinae which prevent them from being everted out.

4. Valves are attached to the wall of the blood vessel. No chordae tendinae are present.

Osmoconformers

Osmoregulators

1. Do not have a constant internal osmolarity. Body fluid concentration rise or fall with the changes in concentration of surrounding medium.

1. Regulate a constant internal osmolarity despite of the different concentration in the surrounding

medium.

2. Body fluid is isotonic to surrounding medium i.e. have same concentration as the sea water outside.

2. Have solute concentration different from their environment.

3. 3. Do not actively control or use energy to control the movement of water. Body surface is permeable to salts and water.

3. Use energy in controlling the movement of water in or out of the body.

4. Have an excellent ability to tolerate wide osmotic range of body fluids

4. Composition of body fluids is within a narrow osmotic range.

5. Examples: Most marine invertebrates, primitive hag fish.

5. Example: All fresh water and land animals, all vertebrates except hag fish and cartilage fish.

Dendron

Axon

Small, numerous and branched.

Long and generally unbranched (one or two).

Have fine terminal branches.

Have terminal end branches with swollen ends.

Conduct the nerve impulse towards the cell body.

Conduct the nerve impulse away from the cell body.

Have Nissl’s granules and Golgi apparatus.

Do not have Nissl’s granules and Golgi apparatus.

Morula

Blastula

A solid ball of cells without a cavity.

A hollow ball of cells having a fluid filled cavity called blastocoel.

An earlier stage, formed as a result of cleavage divisions.

A later stage, formed after the morula stage.

Much smaller in size as blastomeres hardly grow and the cleavage divisions occur rapidly.

Comparatively bigger in size as growth of cells takes place.

Blastula

Gastrula

No movement of cells.

Results from the morphogenetic movement of cells.

Blastula is formed from the morula.

Gastrula is formed from the blastula.

Primary germ, layers are not formed.

Three primary germ layers are distinct.

Presence of the cavity blastocoel; and archenteron is not formed.

Presence of cavity archenteron, also called as primitive gut, blastocoel is highly reduced.

Generally, a hollow ball of cells.

Generally a two layered structure.