Lecture 4 - Biochemistry

Question 1

What is bio chemistry?

Answer 1

Bio chemistry is the study of chemical composition and reactions of living matter

Question 2

Inorganic VS. Organic compounds

Answer 2

In organic does not contain carbon and hydrogen
Ex. Salts, water and many acid and bases

Organic contains both carbon and hydrogen
Ex. Carbohydrates, fats, proteins, nucleic

Both essential for life

Question 3

What is the most important inorganic compound and why?

Answer 3

Water
What accounts for 60% to 80% of the volume in living cells

Most important because of its properties:
High heat capacity
High heat of vaporization
Reactivity
Cushioning

Water is a polar solvent
HYDROPHILIC = water loving
HYDROPHOBIC= water fearing

Question 4

What is Dehydration synthesis?

Answer 4

A covalent bond is created by removing OH from one molecule and H from the other, releasing water

Question 5

What is Hydrolysis?

Answer 5

A covalent bond is broken by adding OH from water to one molecule and H to the other, adding water

Question 6

Salts

Answer 6

Salts are ionic compounds that dissociate into separate ions in water (Strong when dry; weak when wet)

Separate into cations and anions
Also called electrolytes

Salts are an inorganic compound

Question 7

Acids

Answer 7

Acids are proton donors
They release hydrogen ions and bare protons in solution
Ex. HCl —> H+ + Cl-

Inorganic compound

Question 8

Bases

Answer 8

Bases are proton acceptors
They pick up H+ Ions in solution and when dissolved in a solution it releases a hydroxyl ion (OH-)
EX. NaOH —> Na+ + OH-

Bases are inorganic compounds

Question 9

pH

Answer 9

PH scale is a measurement of the concentration of hydrogen ions in a solution
More hydrogen ions = more acidic (higher #)

Question 10

What are buffers, and what is the most important one in your body?

Answer 10

Buffers can act like a weak acid and a weak base releasing hydrogen ions if pH rises or binding hydrogen ions if pH falls

The most important one in the body is the: Carbonic acid bicarbonate buffer system

Question 11

Organic compounds

Answer 11

Contain carbon
Carbon= Electroneutral (Shares but never gains or loses electrons)
Many are polymers (Chains of building blocks called monomers)
Made through dehydration synthesis and broken down by hydrolysis


Question 12

What are carbohydrates?

Answer 12

Carbohydrates include sugar and starches

Monosaccharides: Single sugar units of 3 to 7 carbons
Disaccharides: Double sugar formed by dehydration synthesis of two monosaccharides
Polysaccharides: Large chain of monosaccharides joined together by dehydration synthesis

Question 13

Lipids

Answer 13

Contain C, H, O sometimes P
insoluble in water
MAIN TYPES:
Triglycerides - store energy
Phospholipids- used in cell membranes
Steroids and eicosanoids- signalling molecules (hormones)

Question 14

Triglycerides or neutral fats

Answer 14

Fats when solid, oils when liquid
Main functions are to store energy, insulate and protect

Animals make fats, plants make oils

Question 15

What are Saturated fatty acids?

Answer 15

All carbons are linked via single covalent bonds, usually solid at room temp. Molecule with max number of hydrogen atoms

Question 16

What are unsaturated fatty acids?

Answer 16

One or more carbons linked by double bonds, not saturated with hydrogen atoms and are usually liquids

Question 17

What are phospholipids?

Answer 17

Phospholipids are modified triglycerides made of glycerol and two fatty acids plus a phosphate group

Grouped phospholipids create a bilayer
polar heads and nonpolar tails (amphipathic)


Question 18

Steroids

Answer 18

Consist of four interlocking ring structures of carbon atoms
Ex. Cholesterol which helps in digestion

Question 19

Eicosanoids

Answer 19

Group of unsaturated fatty acids
Prostaglandins are one type of these molecules. They regulate blood pressure and inflammation and reduce sensitivity of pain receptors (NSAIDs) —> aspirin/ ibuprofen