Lesson 1

Question 1

Weak interactions or…

Answer 1

Non covalent interactions

Question 2

Which are the weak interactions? (4)

Answer 2

• Ionic interaction
• hydrogen bonds
• van der Waals interactions
• hydrophobic interactions

Question 3

What are ionic interaction?

Answer 3

• occur between molecules that are charged
• one atom donate electrons to the other
• there is no sharing
• they can attract each other (different charges) or repel each other (same charge)

Question 4

What are hydrogen bonds?

Answer 4

• occur between a hydrogen atom that is covalently bonded to a very electronegative atom such N, O or F atom and another very electronegative atom

Question 5

What is van der Waals interaction?

Answer 5

• occur between two atoms that are uncharged and they are close to each other. In order to molecules to interact, they need to be in a proper distance called Van der Waals radius

Question 6

What is hydrophobic interaction?

Answer 6

• occur between non-polar molecules in aqueous environment. The non-polar molecules tend to get closes together to have just the smallest part of its structure in contact with water.

Question 7

Covalent interactions are stronger than …

Answer 7

• non-covalent interactions

Question 8

RNA and DNA has (which kind of interactions) …

Answer 8

• non-covalent interactions

Question 9

What are the two types of nucleic acids?

Answer 9

• DNA and RNA

Question 10

DNA and RNA are also:

Answer 10

• Nucleotide

Question 11

What compose nucleotides?

Answer 11

• phosphate: monophospate, diphosphate and triphosphate
• pentose: DNA (deoxyribose) and RNA (ribose)
• nitrogenous base

Question 12

In DNA or RNA we will see only …

Answer 12

• monophosphate

Question 13

Nitrogenous base (purines):

Answer 13

• only has two rings (adenine and guanine)

Question 14

Nitrogenous base (pyrimidines):

Answer 14

• only has one ring (thymine, cytosine and uracil)

Question 15

Thymine:

Answer 15

• only exist in DNA

Question 16

Uracil:

Answer 16

• only exist in RNA

Question 17

Adenine:

Answer 17

• will pair with thymine (DNA) or to uracil (RNA) with 2 hydrogen bonds

Question 18

Guanine:

Answer 18

• will pair to cytosine with 3 hydrogen bonds

Question 19

What compose carbohydrates?

Answer 19

• carbon, hydrogen and oxygen

Question 20

Polymers of carbohydrates are made of?

Answer 20

• monomers and that are called monosaccharides

Question 21

What the main function of carbohydrates?

Answer 21

• gives energy and energy storage

Question 22

How is formed a carbohydrates?

Answer 22

• carbonyl group (aldehyde and ketone) + alcohol groups

Question 23

5 or more carbons form a:

Answer 23

• ring group (hydroxyl group does a nucleophilic attack on the carbonyl group)

Question 24

Which are the monosaccharides? (4)

Answer 24

• glucose: our main source of energy

• fructose: found in honey, fruit and vegetables

• galactose: milk sugar, found in nature when bound glucose to form lactose

• deoxyribose and ribose: part of nucleic acids (DNA and RNA respectively)

Question 25

Which are the disaccharides? (3) (When 2 monosaccharides bounds together)

Answer 25

• sucrose: glucose + fructose - it’s found in fruits and vegetables. Alfa 1-2 glycosidic bond.

• lactose: glucose + galactose - it’s found in the milk of mammals (sugar cane and sugar beets). Beta 1-4 glycosidic bond.

• maltose: glucose + glucose - it’s found in molasses. Alfa 1-4 glycosidic bond.

Question 26

What is oligosaccharides?

Answer 26

• it’s when 3 to 9 saccharides bound together

• galacto-oligosaccharides= short chains of galactose molecules like those found in soybeans.

Question 27

What is polysaccharides? (3)

Answer 27

• it’s when 10 or more saccharides bound together

• starch (plant energy storage) = it’s composed of amylose and amylopectin. It can be found in rice, potatoes, wheat and maize. They are not sweet and the intestinal enzymes are able to digest them

• glycogen (animal energy storage)

• ** cellulose** (part of plant’s cell walls) = it’s a dietary fiber, so our intestinal enzymes cannot digest it

• all polysaccharides are made from glucose molecules

Question 28

What are lipids made from?

Answer 28

• they are most made of C-H bonds (hydrocarbons), but they contain oxygen, phosphate and nitrogen

Question 29

Lipids can be soluble in water?

Answer 29

• most of them CANNOT

• some lipids are hydrophobic, but some can be amphipathic

Question 30

Lipids are NOT:

Answer 30

• polymers

Question 31

What are proteins?

Answer 31

• they are polymers build from monomers called amino acids

Question 32

Which are proteins’ functions? (8)

Answer 32

• structure of cells
• catalysis of reaction (as enzymes)
• hormones
• muscle contraction
• growth
• storage
• repair
• DNA replication and transcription