Chemistry of life

Question 1

What is biochemistry?

Answer 1

The chemistry of life and its building blocks. It explores the chemical processes within and related to living organisms.

Question 2

What is an atom?

Answer 2

The smallest unit of matter that have a tiny centra; nucleus which contains protons and neutrons.

Question 3

How many naturally occurring elements are there?

Answer 3

92

Question 4

4 most common elements

Answer 4

carbon, hydrogen, oxygen and nitrogen

Question 5

what is the atomic numebr?

Answer 5

The number of protons in an atom’s nucleus. (the atomic differentiates one element from another, as each one has its own atomic number).

Question 6

Atomic weight

Answer 6

The sum of protons and neutrons in the atomic nucleus.

Question 7

What are electrons?

Answer 7

These represent the energy levels of atoms by orbiting/surrounding the nucleus of an atom in circular rings. (also known as electron shells; where only maximum numbers of electrons can be held within each shell depending on its position to the atom (e.g. closest; 1 electron, second closest; 8 electrons, etc.)

Question 8

What happens when an atom’s outer shell’s contain an unstable number of electrons?

Answer 8

the atom will be reactive and may donate, share or receive electrons with one or more other atoms achieve stability.

Question 9

What is a molecule?

Answer 9

A group of two or more atoms that are chemically combined. Atoms can be of the same element or of two or more different elements.

Question 10

Difference between organic and inorganic compounds?

Answer 10

Compounds containing carbon & hydrogen are organic, whilst all other compounds are inorganic.

Question 11

What is a compound?

Answer 11

A substance consisting of atoms or ions of two or more different elements in definite proportions joined by chemical bonds into a molecule.

Question 12

What is a covalent bond?

Answer 12

when atoms share their electrons together. most molecules are held together by this type of bond. an example of this is a water molecule; two hydrogen atoms & one oxygen atom.

Question 13

What is an electrolyte?

Answer 13

an iconic compound/ a substance that that produces an electrically conducting solution when dissolved in a solvent, such as water. e.g. calcium

Question 14

What is an ion?

Answer 14

an atom or molecule with a a net electrical charge that bear one or more positive or negative electrical charges

Question 15

What are biomolecules (biological molecules) & types?

Answer 15

Any type of the numerous substances that are produced by cells and living organisms, with the main types being;

• carbohydrates- sugar molecules made up of carbon, hydrogen & O2
• lipids- (fats & oils) made up up of glycerol and fatty acids
• proteins- made up of many amino acids

Question 16

What is pH?

Answer 16

The measuring system used to quantify the concentration of hydrogen ions in a fluid, which is an indicator of its acidity or alkalinity. (pH test measures the amount of hydrogen ions in a given solution).

• 0.0-6.0 is acidic -e.g. stomach acid
• 7.0 is neutral -e.g. water
• 7.1-14.0 is alkaline -e.g. blood

Question 17

What are hydrogen ions?

Answer 17

a hydrogen ion is created when a hydrogen atom loses or gains an electron. high concentrations of this ion produce a low pH whilst low concentrations produce a high pH.

Question 18

What are nucleotides?

Answer 18

the basic building block of nucleic acid which consists os a sugar molecule. nucleic acids are the largest molecules in the body and built from nucleotides. ATP is a nucleotide.

Question 19

What are buffers?

Answer 19

Buffers maintain internal stability despite constant cellular production of acids & bases. examples of buffers are;

• lungs; important regulators of blood pH as they excrete CO2
• kidneys; also regulate blood pH by adjusting excretion of excess waste

Question 19

What are buffers?

Answer 19

Buffers maintain internal stability despite constant ceullar porcution of acids & based

Question 20

What is diffusion?

Answer 20

Diffusion is the movement of molecules down a concentration gradient, from a high concentration gradient to a low one, until an equilibrium (balance) is reached. Diffusion is sped up by heat and can pass through a semi-permeable membrane such as a cell’s plasma membrane & capillary walls.

Question 21

Example of diffusion;

Answer 21

Diffusion occurs in the lungs during respiration. O2 diffuses from the lungs into the capillaries bloodstream surrounding alveoli (air sacs), and CO2 crosses from the capillaries into the air sacs to be exhaled.

(bigger molecules such as RBCs and WBCs don’t leave the capillary bloodstream and into the alveolus because they are too big to pass through).

Question 22

What is osmosis?

Answer 22

Osmosis regards the movement of water molecules from a high water concentration to a low one, down a concentration gradient, until equilibrium is reached.

Question 23

Osmosis example;

Answer 23

Osmosis can be understood through the structural change of RBCs;

• If blood plasma is hypotonic (more dilute than the ICF than within the RBC), water will enter the cell, causing the erythrocyte to swell and burst.
• If the ICF is of a stronger concentration than that of the ECF which is blood plasma, the cell’s ICF will passively move out of the cell, causing the erythrocyte to shrink and become flacid.

Question 24

What is active transport?

Answer 24

the transport of substances against a concentration gradient, from a region of lower concentration to a region of higher concentration. (going against the concentration gradient). this is driven by ATP, a chemical energy which pushes protein carriers transporting molecules across a membrane in the right direction. (downhill to uphill movement.

Question 25

Primary active transport

Answer 25

active transport that directly uses ATP for energy

Question 26

Secondary active transport

Answer 26

moves multiple molecules against the membrane, powering uphill movements of molecules (A) whilst powering the downhill movements of others (B).

Question 27

what is ATP

Answer 27

ATP- adenosine triphosphate is an organic compound that provides energy which drives many processes in living cells. (the primary carrier of energy in cells). ATP captures chemical energy obtained from broken down food molecules and releases it to fuel other cellular processes, like a messenger of energy;

• to transport needed substances against concentration gradients, (active transport)
• mechanical work such as moving muscles

Question 28

what are enzymes/biological catalysts?

Answer 28

Enzymes are proteins that function as biological catalysts (a substance that changes the rate of a chemical reaction without being changed by the reaction itself). Enzymes are folded into a 3D shape which allows smaller molecules to fit into them