Lecture 1 - Chemistry of Life and The Cell

Question 1

From what 30
small precursors are molecular structures in organisms built from?

Answer 1

20 amino acids, 2 purines, 3
pyrimidines, sugars (glucose and ribose), palmitate,
glycerol and choline

Question 2

What is the human body composed of ?

Answer 2

60% water, 15%
proteins, 15% lipids, 2% carbohydrates and 8%
minerals

Question 3

What does compartmentation of cells promote and how?

Answer 3

Efficiency by maintaining high local concentrations of reactant

Question 4

What have metabolic pathways evolved to do?

Answer 4

Synthesize molecules and generate energy

Question 5

What are the simplest cells?

Answer 5

prokaryotes

Question 6

What are eukaryotes are characterized by?

Answer 6

Numerous membrane-bounded organelles, including a nucleus

Question 7

The phylogenetic tree of life includes what three domains?

Answer 7

Bacteria, archaea, and eukarya

Question 8

How does evolution occur?

Answer 8

Evolution occurs as natural selection acts on randomly occurring genetic variations among individuals.

Question 9

What are the STABILIZING FORCES IN MOLECULES?

Answer 9

Covalent, Ionic or Electrostatic, Hydrogen bonds.

Question 10

Covalent Bonds

Answer 10

Formed by sharing of electrons between atoms

Question 11

Ionic Bonds or Electrostatic Bonds

Answer 11

Result from the electrostatic attraction between two ionized groups of opposite charges
-One or more electrons from the outermost orbit of an electropositive atom transfer to the outermost orbit
of an electronegative atom

Question 12

Hydrogen Bonds

Answer 12

Sharing of a hydrogen between two electron donors
- electrostatic attraction between an electro-negative atom and a hydrogen atom that is bonded covalently to a second electronegative atom

Question 13

What are electrolytes?

Answer 13

Molecules that dissociate in water form cations (positively charged ions) and anions
(negatively charged ions) because the ions facilitate
conductance of an electrical current

Question 14

Sugars or alcohols are….

Answer 14

nonelectrolytes because they dissolve readily in water but do not
carry a charge or dissociate into charged species

Question 15

What does blood pH reflect ?

Answer 15

Changes in pH in tissues

-  values above or below the normal range of pH of 7.35 to 7.45 indicates a potential pathological condition

Question 16

What pH values are life threatening?

Answer 16

values below 7.0 (H+ = 0.0000001 M) or above 7.8 (H+= 0.000000016 M)

Question 17

What are medical conditions referred to if the blood pH drops below and above the norm?

Answer 17

If the blood pH falls below 7.35, the condition is referred to as acidosis, and above 7.45, as an alkalosis

Question 18

Conditions of acidosis or alkalosis are further defined based on what?

Answer 18

the source of the increase of acid or base in the body, that
is, whether it is due to a metabolic or respiratory change

Question 19

Properties of Eukaryotic Cell

Answer 19

Size= Small or Large 1000 to 10000 times
Cell wall= Rigid or Membrane of lipid bilayer
Nucleus= Not defined or Well defined
Organelles= Nil or Several including mitochondria and lysosomes