Macromolecules: Carbs + Lipids

Question 1

what are macromolecules? what are the four types?

Answer 1

Large biologically important organic molecules

1. Carbohydrates
2. Lipids
3. Nucleic acids
4. Proteins

Question 2

what is a polymer?

Answer 2

a long chain-like molecule consisting of many similar/identical subunits (monomers) linked by covalent bonds

Question 3

what is a monomer?

Answer 3

a molecule that can be bonded to other identical molecules to form a polymer

Question 4

does each type of macromolecule have the same or different monomer? how does the breakdown/synthesis of polmers differ?

Answer 4

• different
  -Chemical mechanism of making and breaking
  polymers is the same

Question 5

how are polymers made, what is this reaction called? does it require energy?

Answer 5

Dehydration reaction (or condensation reaction)

• Monomers are covalently bonded (two of the same molecules) through the loss of a water molecule
• Requires energy; typically involves an enzyme
• ie. water removed, new bond formed

Question 6

how do polymers breakdown, what is this called? does it require energy?

Answer 6

hydrolysis

• Bond between monomers broken by addition of water
• no, typically results in the release of energy
• ie. water added, bond broken

Question 7

what is a carbohydrate monomer called? 2 monomers called? a polymer called?
what holds 2+ monomers together?

Answer 7

• monosaccharides
• Disaccharide
• Polysaccharides
• covalent bonds formed by a dehydration reaction

Question 8

what are monosaccharides? what is their general formula? what is an exxample of a simple sugar?

Answer 8

• simple sugars
• CH2O
• eg. ribose, deoxyribose, glucose

Question 9

what are the 2 main functions of simple sugars?

Answer 9

• major source of energy in a cell

- raw material for synthesis of other organic molecules

Question 10

structure of a sugar:

1. how many carbons in length are sugars?
2. what is the structure of atoms/ions attached to carbons (functional groups bound to carbons)
3. how is it drawn?

Answer 10

1. range from 3 - 6 carbons in length
2. One of the carbon atoms has a carbonyl bound to
   it -> C=O
   -the other carbons have hydroxyls bound to them –> -OH
3. Can be drawn in linear form or ring form

Question 11

what 2 functions can polysaccharides have?

Answer 11

1. storage molecules (store energy)

2. building material

Question 12

what polymers do plants store energy in? what polymers do animals store energy in?
what is the disadvantage/advantage of these polymers?

Answer 12

plants -> starch
-disadvantage: heavy, stored in roots
animals -> glycogen
-advantage: much light than starch, for better for organisms that are motile

Question 13

what shape are storage polysaccharides? why? what is the advantage of this shape?

Answer 13

helical

• because glucose monomers all in same orientation
• advantage of being helical: they take up less space because they squish, so maximizes space for energy storage

Question 14

what is a structural polysaccharide, what is it used for?

Answer 14

Cellulose polymer

-used to build plant cell walls

Question 15

what shape are structural polysaccharides? why? what is the advantage of this shape?

Answer 15

linear

• because glucose monomers alternate their position in respect to neighboring monomers
• advantage is that it is stronger and more rigid

Question 16

what does the orientation of glucose monomers in a polymer change?

Answer 16

changes the structure and function of the polymer

Question 17

what polysaccharide is present in the exoskeleton of

arthropods and in the cell walls of fungi? how is it similar to cellulose?

Answer 17

chitin

-Similar to cellulose in its struicture, except that the glucose monomer also has a nitrogen-containing group

Question 18

lipids are :
hydrophilic or hydrophobic?
what kind of bonds are lipids composed of?
what 2 element are they primarily composed of?

Answer 18

hydrophobic

• hydrocarbon regions (typically the majority) are composed of nonpolar covalent bonds (nonpolar regions); while additional molecules are often polar bonds
• carbon and hydrogen

Question 19

what are hydrocarbons?

Answer 19

is an organic compound consisting entirely of hydrogen and carbon

Question 20

hydrocarbons/hydrocarbon regions are: polar/nonpolar?

Answer 20

nonpolar!

Question 21

are lipids polymers?

Answer 21

lipids are large biological molecules but not polymers

Question 22

what are 3 biologically important types of lipids?

Answer 22

1. Fats
2. Phospholipids
3. Steroids

Question 23

what is a fatty acid? how many carbons does it contain? is is mostly polar or nonpolar?

Answer 23

long carbon chain with a carboxyl group at one end

• 16 - 18 carbons
• typically mostly nonpolar

Question 24

what are fats made of? what kind of bond/how are the components bonded?

Answer 24

Composed of glycerol and fatty acids
-covalent bond between glycerol and fatty acid, achieved by removal of water molecule between them
(the OH of the carboxyl of the fatty acid bonds with an H of an OH of the glycerol)

Question 25

what are fat molecules made of? what are they called?

Answer 25

triglyceride 1 glycerol 3 fatty acids

Question 26

what are saturated fats? are they solid or liquid at room temperature, why? give example

Answer 26

- fats that have fatty acids that have no double bonds between carbon atoms, meaning all carbons sharing one pair of electrons - solid; because fat molecules are able to pack tightly together because of their shape - eg butter, cheese, most animal fats

Question 27

what are unsaturated fats? are they liquid or solid at room temperature? give example

Answer 27

- fats that have fatty acids that have one or more double bonds between carbon atoms - Liquid; because double bonds cause a kink in the hydrocarbon chain, meaning fat molecules can not pack as tightly together, also can change shapely continuously - Most plant and fish fats are unsaturated

Question 28

what are fats used for? why? especially for what organisms?

Answer 28

used for energy storage -because more compact form of energy storage than carbohydrates -especially for organisms that move because it is more light and compact

Question 29

what are phospholipids composed of?

Answer 29

glycerol + 2 fatty acids + phosphate

Question 30

in a phospholipid the tails are: are they hydrophobic or hydrophilic, why? the heads are: are they hydrophobic or hydrophilic, why?

Answer 30

tails: Hydrocarbon fatty acids - hydrophobic, because they are made of nonpolar bonds btw atoms heads: Phosphate - hydrophilic because they are made of polar bonds btw atoms

Question 31

what are phospholipids a major components of? how are they arranged?

Answer 31

cell membranes -composed of a bilayer of phospholipids -Hydrophilic heads on outside of bilayer interacting with water -Hydrophobic tails on inside of bilayer, away from the water

Question 32

what are steroids? give an example of a steroid and what is does

Answer 32

Lipids with carbon skeleton consisting of 4 fused rings -choletesterol - part of cell membranes and precursor to many hormones -> fits in between phospholipids