Biochemistry

Question 1

What are the most abundent elements in living matter?

Answer 1

Hydrogen, Carbon, Nitrogen, Oxygen, Phosphorus, Sulfur

Question 2

How are molecules formed?

Answer 2

Atoms create chemical bonds which form interacts of the electrons with the same or different elements

Question 3

What is a compound?

Answer 3

A molecule made up of atoms from at least 2 different elements

Question 4

What are ions?

Answer 4

Molecules with an electrical charge

Question 5

What are anions?

Answer 5

Anions are more stable with more electrons than protons so carry a negative charge

Question 6

What are cations?

Answer 6

Cations are more stable with less electrons than protons so have a positive charge

Question 7

What is a radical?

Answer 7

A group of atoms behaving as a unit in a number of compounds and is an ion with unpaired electrons

Question 8

What is a chemical reaction?

Answer 8

When 2 substances mix and interact to form a new chemical e.g. burning

Question 9

What is the principle of mass concervation and how is it related to chemical reactions?

Answer 9

Atoms are rearranged not, not lost or gained- in reversible reactions and reactions involving ions adhere to charge conservation; there is no net increase just redistribution

Question 10

What is pH?

Answer 10

the concentration of protons/ H+ in a solution (1= acidic-high H+, 14=alkaline- low H+)

Question 11

What are the major structures of a cell?

Answer 11

Endoplasmic reticulum, ribosomes, nuclear envelope, lysosome, nucleus, nucleolus, cytosol, chromatin, golgi apparatus, mitochondrion, plasma membrane, endoplasmic reticulum

Question 12

What does the golgi apparatus do?

Answer 12

Secretion

Question 13

What does the endoplasmic reticulum do?

Answer 13

Sysnthesis and storage

Question 14

What do ribosomes do?

Answer 14

Production

Question 15

What do lysosomes do?

Answer 15

Breakdown

Question 16

What does the nucleolus do?

Answer 16

rRNA

Question 17

What does the nucleus do?

Answer 17

DNA

Question 18

What does the mitochondria do?

Answer 18

Energy production (ATP)

Question 19

The atomic number is an indicator of?

Answer 19

number of protons

Question 20

What is the unit of measurement for atomic mass?

Answer 20

Dalton/Amu

Question 21

What is metabolism and its processes?

Answer 21

Metabolism is the sum of chemical reactions occuring in a living organism or part of it
Metabolites undergo metabolic reactions to create a path way which change/liberate energy

Question 22

What effects factors in the metabolism of hydrolysis of urea?

Answer 22

Chemical thermodynamics-energy changes in chemical systems and are applied to living organisms in the study of bioenergetics

Question 23

What is free energy/ΔG?

Answer 23

Energy that is available to perform thermodynamic work at constant temperature, i.e., work mediated by thermal energy. Free energy is subject to irreversible loss in the course of such work.

Question 24

What is the formula for free energy?

Answer 24

ΔG=ΔH-TΔS

free energy= enthalpy - temperature entropy

Question 25

What is ΔH/enthalpy?

Answer 25

It is equal to the total bond energy/ energy required to break covalent bonds

Question 26

What is entropy/S?

Answer 26

Disorder or randomness- increases in a system that becomes more disordered, decreases in a system as it becomes more structured. Many biological reactions result in an increase in order, thus an increase in S

Question 27

What affects the ΔG/free energy of a reaction?

Answer 27

Temperature, pressure, pH and initial amounts of reactants & products

Question 28

What is ΔG°’?

Answer 28

The standard free energy change of a reaction- value of the change in free energy under standard coditions during a reaction (25C, 1 atm pressure, pH 7)

Question 29

What What does this equation work out? | ΔG=ΔG + RT InQ=ΔG°’ + RT In (products/reactants)

Answer 29

``` It estimates free energy changes for different temperaturesand initial concentrations R= gas constant (1.987 cal/degree/mol) T= temperature Q=initial ratio of product to reactants Measured in kcal ```

Question 30

What is an exergonic reaction?

Answer 30

ΔG<0 free energy of the products is lower than the reactants; a favoured reaction where energy is liberated for work- cycling downhill

Question 31

What is endergonic?

Answer 31

ΔG>0 free energy of products is higher than the reactants; unfavoured reaction where energy is used up- cycling up hill

Question 32

DEscribe ATP and reactions involving it

Answer 32

ATP is the energy currency for cells ATP+H20⟺ADP+Pi+Hᐩ ΔG°1=-6.3 kcal.mol^-1 ATP+2H20⟺AMP+2Pi+H+ ΔG°1=-12kcal.mol^-1 Second one is very negative ΔG°1 so favoured thermodynamically and ATP referred to as a high energy compound