Chapter 2 - Atoms and Molecules (Done)

Question 1

Most abundant element in our body

Answer 1

Oxygen

approximately 70% of body mass

Question 2

Essential elements

Answer 2

25 essential elements 
1) major elements (96.3%) 
O > C > H > N
2) minor elements (3.7%) 
Na+, Cl-, K+, S, P 
3) trace elements (0.01%)

Question 3

Amount of blood in our body

Answer 3

4.5~5.5 liters

Question 4

Iron (Fe) as trace element

Answer 4

-essential component of hemoglobin in RBCs which consist of 40-45% of blood

Question 5

Iodine (I2, I-) as trace element

Answer 5

• essential component of thyroxine, a type of thyroid hormone
• influences body metabolism

Question 6

Zinc (Zn) as trace element

Answer 6

-important component of semen

Question 7

Valence

Answer 7

bonding capacity of an atom

equals to the number of unpaired electrons required to complete the valence shell

Question 8

PET

Answer 8

Positron Emission Tomography

-radioactive labelled glucose injected

Question 9

Radioactive particles released by radioisotopes

Answer 9

alpha: nucleus of He2+
beta: electrons
gamma: energy wave

Question 10

Energy

Answer 10

capacity to cause change

Question 11

Potential energy

Answer 11

energy due to structure, location and concentration gradient
e.g. chemiosmosis, electrical impulse

Question 12

Orbital

Answer 12

• derived from Heisenberg’s uncertainty principle

- atomic/molecular orbital can be used to determine the molecule using VSEPR (valence shell electron pair repulsion)

Question 13

VSEPR

Answer 13

valence shell electron pair repulsion
-theory assuming that each atom in a molecule will achieve a geometry that minimizes repulsion between electrons in the valence shell of that atom

Question 14

Non-polar covalent bond

Answer 14

electronegative difference of < 0.4

Question 15

Polar covalent bond

Answer 15

electronegative difference of 0.4 < x < 1.7

Question 16

Hydrogen bonds

Answer 16

bond between partial positive hydrogen atom in one molecule with partially negative F, O, N atoms in another molecule within a single polar molecule

Question 17

analgesics

Answer 17

painkiller

e.g. morphine, a molecular mimic of endorphin made from opiates

Question 18

Dynamic equilibrium

Answer 18

the rate of forward reaction is equal to the rate of reverse reaction
-reaction rate is affected by: concentration, temperature, pressure
(ΔG = 0)