Bio Lecture 3 and 4

Question 1

What is a dehydration reaction?

Answer 1

When 2 monomers bond together into a polymer through the loss of a water molecule

Question 2

What is a hydrolysis reaction?

Answer 2

Polymers are disassembled into monomers by adding a water molecule

Question 3

What are carbohydrates

Answer 3

Serve as fuel and building material. The simplest carbohydrates are monosaccharides. Carbohydrate macromolecules are polysaccharides which are polymers composed of many sugar building blocks

Question 4

Explain monosaccharides

Answer 4

Molecular formulas that are usually multiples of CH2O
Glucose is the most common
Have glycosidic linkages
Classified by number of carbons and location of carbonyl group

Question 5

Explain polysaccharides

Answer 5

Polymers of sugar that have storage and structural roles
Structure and function determined by sugar monomers and position of glycosidic linkages

Question 6

Give examples of storage polysaccharides

Answer 6

Starch consists entirely of glucose monomers
Glycogen in animals in liver and muscle cells. Hydrolysis of glycogen release glucose when the demand for energy increases

Question 7

Give examples of structural polysaccharides

Answer 7

Cellulose is a major component of plant cell walls and is a polymer of glucose
Chitin - found in arthropod exoskeletons

Question 8

Why do the glycosidic linkages of cellulose differ from those of starch

Answer 8

Ring forms of glucose in the 2 polymers are slightly different. Cellulose contains beta glucose instead of alpha glucose in starch

Question 9

What are lipids?

Answer 9

One class of large biological molecules that does not form polymers. Unifying feature of lipids is little or no affinity for water

Question 10

Why are lipids hydrophobic?

Answer 10

Because they consist mostly of hydrocarbons which are non polar

Question 11

Examples of lipids

Answer 11

• fats
• phospholipids
• steroids

Question 12

What are fats constructed from?

Answer 12

Glycerol and fatty acids

Question 13

What is glycerol?

Answer 13

A three carbon alcohol with an hydroxyl group attached to each carbon

Question 14

What do fatty acids consist of??

Answer 14

Carboxyl group linked to a long hydrocarbon chain

Question 15

Describe fatty acids

Answer 15

Three fatty acids are joined to glycerol by water linkages to form triglyceride
Vary in length, number and location of double bonds
Saturated fatty acids do not have double bonds and are solid at room temp
Unsaturated fatty acids have one or more double bonds and are liquid at room temp

Question 16

A diet rich in….. may contribute to cardiovascular disease

Answer 16

Saturated fats

Question 17

Definition of hydrogenation

Answer 17

Process of converting unsaturated fats to saturated fats, creates unsaturated fats with trans double bond. These trans fats may contribute more than saturated fats to cardiovascular disease

Question 18

What are essential fatty acids?

Answer 18

Certain Unsaturated fatty acids are not synthesized in the human body and must be supplied through diet

Question 19

Major function of fat

Answer 19

Energy storage

Question 20

What are phospholipids?

Answer 20

Two fatty acids and a phosphate group attached to glycerol. The two fatty acid rails are hydrophobic and the phosphate head group is hydrophilic

Question 21

Protein functions include

Answer 21

– Speeding up (catalyzing) chemical reactions
– structural support
– storage
– transport
– cellular communications
– movement
– defense against foreign substances

Question 22

Receptor proteins

Answer 22

Response of cell to chemical stimuli

Question 23

polypeptides

Answer 23

Amino acids are linked together into unbranched polymers

Question 24

Amino acids are

Answer 24

organic molecules with
carboxyl and amino
groups

Question 25

Amino acids are linked by

Answer 25

peptide bonds

Question 26

Primary structure

Answer 26

the sequence of amino acids

Question 27

Secondary structure

Answer 27

Results from hydrogen bonds between repeating constituents
* Typical secondary structures include:
– coil called an α-helix, and
– folded structure called a β-pleated sheet

Question 28

Tertiary structure

Answer 28

Is the overall shape of a polypeptide, and is determined by interactions between R groups

Question 29

Quaternary structure

Answer 29

results when two or more polypeptide chains form one macromolecule

Question 30

Two types of nucleic acids

Answer 30

Deoxyribonucleic acid (DNA)
Ribonucleic acid (RNA)

Question 31

Shape of the nucleus is maintained by

Answer 31

nuclear lamina

Question 32

Components of endomembrane system

Answer 32

– Nuclear envelope
– Endoplasmic reticulum
– Golgi apparatus
– Lysosomes
– Vacuoles
– Plasma membrane

Question 33

Smooth ER

Answer 33

• Synthesizes lipids
• Metabolizes carbohydrates
• Detoxifies drugs and poisons
• Stores calcium ions

Question 34

Rough ER

Answer 34

Has bound ribosomes, which synthesize glycoproteins
Produces transport vesicles, which distribute lipids and proteins to other
components of the endomembrane system

Question 35

Lysosome

Answer 35

membrane-bound compartment of
hydrolytic enzymes that can digest macromolecules
* Lysosomal enzymes can hydrolyze proteins, fats, polysaccharides, and nucleic acids
* Lysosomal enzymes work best in acidic environment inside lysosome

Question 36

phagocytosis

Answer 36

Some cells can engulf
another cell