Elementary Biochemistry(part1)

Question 1

What is the definition of transpiration?

Answer 1

Transpiration is the loss of water vapour from a plant to the outside atmosphere through the leaves of the stomata.

Question 2

What is the phloem and xylem?

Answer 2

Phloem is specialized in the transport of organic and inorganic materials within the plants and the xylem conducts water and minerals from upwards from the roots to all parts of the plant.

Question 3

What does the blood do?

Answer 3

It transports nutrients and gases and carries away metabolic water from organs.

Question 4

Describe water and its molecule

Answer 4

Water(polar molecular) consists of hydrogen(1 electron) and oxygen(8 electrons, 6 take part in bond formation). It has 1 oxygen atoms and 2 hydrogen atoms bonded together also has 2 covalents bonds which hold the atoms in the molecule together.

Question 5

What are orbitals?

Answer 5

Orbitals are the regions around atomic nuclei in which electrons may be found. It can contain 1 or 2 electrons or it can be empty.

Question 6

What is the difference between oxygen and hydrogen?

Answer 6

Oxygen(negative charge) has a higher capacity to attract electrons than hydrogen(positive charge) does, meaning it has a higher electronegativity.

Question 7

What is a hydrogen bond?

Answer 7

A hydrogen bond is formed when regions of a water molecule with a small positive charge come close to a negatively charge region of another water molecule.

Question 8

What are properties of water?

Answer 8

cohesion and surface tension
freezing and density
heat of fusion and vaporisation
heat capacity of water

Question 9

What is a solution?

Answer 9

A solution is a uniform mixture of molecules or ions of two or more substances.

Question 10

What is a solute and a solvent?

Answer 10

Solvent is the liquid substance in greater amount
Solute is the liquid substance in lesser amount

Question 11

What is hydrophilic & hydrophobic

Answer 11

Hydrophillic(water loving) & hydrophobic(water hating)

Question 12

What are acids and bases?

Answer 12

Acid(protons donors) is a substance that causes the concentration of hydrogen ions to rise above its equilibrium value of 1 * 10-7 mol L-1.

Base(proton acceptors) is a substance that causes a decrease in the relative numbers of H or alternatively an increase in the relative number of OH- in a solution.

Question 13

What are buffers?

Answer 13

Buffers are chemical systems that maintain a relatively constant pH when small amounts of acid or base are added to a solution.