Module 2, Part 3 of 3

Question 1

Inorganic vs Organic

Answer 1

Inorganic:
-simple structure
-elements: may have C but not usually
-carries out biological functions: NO
-covalent bonds: sometimes

Organic:
-complex structure
-elements: always C bonded to H
-carries out biological function: yes
-covalent bonds: sometimes

Question 2

Functional Groups

Answer 2

group of atoms in a molecule with distinctive chemical properties

Question 3

Hydroxyl Group

Answer 3

O-H = hydroxyl group, polar, hydrophilic (alcohols such as ethanol for killing bacteria and soe viruses)

Question 4

Amino Group

Answer 4

N-H = amino group, found on proteins, buffer in kidney to act as weak base and take on H+, polar and hydrophilic

Question 5

Carbonyl Group

Answer 5

C=O = carbonyl group (aldehyde if on end), if in middle they are a ketone, polar and hydrophilic, formaldehyde

Question 6

Ketone Group

Answer 6

C=O in middle of structure = ketone, acetone in nail polish remover, we make ketones when we metabolise proteins

Question 7

Carboxyl Group

Answer 7

COOH
-carbonyl CO + hydroxyl OH
-hydrophilic
polar

Question 8

Amino Acid Structure:

Answer 8

-amino group
-r side chain
-carboxyl group
-we have 21 amino acids in body, 9 of them are essential to eat in our diet
-ex. Cysteine, tyrosine, alanine

Question 9

disulphide bonds not involved in secondary structure

Answer 9

disulphide bonds not involved in secondary structure

Question 10

Protein Structures:

Answer 10

-amino acids chain
-alpha helix/pleated sheet = secondary protein structure of hydrogen bonds
-tertiary structure is 3 menial folding due to H-bonds, disulphide bonds (sulphurs in R-chains), ionic bonds
-quaternary structure = protein consisting of more than 1 amino acid chain

Question 11

Carbohydrates:

Answer 11

-key energy source for cells (used to generate ATP)
-contains only C, H, O
3 main forms; mono, di and polysaccharides
-monosaccharides = pentose (5C) and hexose (6C)
Monosaccharides combine to make disaccharides via dehydration thetis (form glycosidic bond)
-breakdown disaccharides via hydrolysis with the help of enzymes
-Polysaccharides are effectively stored as they are insoluble in water
-Main storage polysaccharide is glycogen in liver and skeletal muscle

Question 12

Case Study: a 6 month old infant has been fed formula. Child develops jaundice, hepatomegaly, vomiting, lethargy, irritability and seizures after trying fruit juice

Answer 12

-baby has fructosemia (can’t digest fructose)
-lack of required enzymes cause interruption of a normal metabolic pathway and an accumulation of metabolic precursor, food is broken down improperly and vital organ damage is caused
-Tx. Avoid fructose

Question 13

Lipids:

Answer 13

-hydrophobic (insoluble in water)
-1. Fatty acids (carboxyl group on end of carbon chain)
-2. Lipids containing glycerol (lipid contains with 3 fatty acids to make triglyceride)
-3. Steroids (3 cyclohexane and 1 cyclopentane)

Question 14

Saturated fatty acids:

Answer 14

solid at room temp, saturated with hydrogen
-play an important role in hormone production, cardiovascular health, gene transcription, lipogenesis, apoptosis, cellular membrane structure, and protein signalling

Question 15

fatty acid with amide linked polar groups:

Answer 15

sphingolipid
=nervous syste, sognalling

Question 16

eicosanoids

Answer 16

are are fatty acids that signal cell and tissue function (usually about 20 bent carbons)
prostaglandins and leukotrienes and thromboxanes are examples of eicosanoids

Question 17

arachidonic acid

Answer 17

arachidonic acid is a precursor to eicosanoids

Question 18

Why Should Aspirin and NSAIDs be Avoided in Pregnancy:

Answer 18

-prevents clotting so dont give during labour
-blocks production of prostaglandins
Aspirin/NSAIDs block COX-2 enzyme
This doesn’t close ring so we can make eicosanoids
Causes decreased thromboxane (thromboxane aids in blood clotting)
-Thromboxane helps platelet aggregation, causing excessive bleeding and less clotting
-thromboxane decreases prostaglandin that leads to closing of ductus arteriosus in baby
-decreased prostaglandins reduces pain (prostaglandins cause high pain sensory)
-can close baby’s ductus arteriosus during pregnancy

Question 19

Naming Fatty Acids:

Answer 19

-count carbons/points, then omega
PRACTICE!

Question 20

Phospholipids:

Answer 20

-have a choline, phosphate, polar head group, glycerol backbone, fatty acid chain
-hydrophilic head
-hydrophobic tail
-do energy transfer/breakdown of ATP, intracellular signalling, membrane structure

Question 21

Steroids:

Answer 21

-2 major groups: metabolic (mineralocorticoids and glucocorticoids made in adrenal glands), and sex hormones (progesterone, oestrogen and androgens made in gonads)
-cholesterol is a precursor to make homrones

Question 22

How Steroids Act:

Answer 22

-can’t move freely in blood as they are not water soluble
-instead they move attached to a transport protein
-hormone enters cell and binds to intracellular receptors
-the hormone/receptor complex bind specific hormone response elements in DNA
-see certain genes will be turned on and the contain protein will be made to exert effects