2.1 Molecular Biology (Water, Carbohydrates, Lipids)

Front 1

Common organic elements

Back 1

Hydrogen, Oxygen, Carbon, Nitrogen

Front 2

Hydrophobic

Back 2

Will not interact with water, eg: fatty acid

Front 3

Hydrophilic

Back 3

Affinity for and interacts with water, eg: salts, Vitamin C

Front 4

Amphipathic

Back 4

Molecule that is part hydrophobic and part hydrophilic

Front 5

Cohesion (water)

Back 5

Formation of hydrogen bonds with other water molecules

Front 6

Adhesion (water)

Back 6

Polarity of water makes it attracted to other molecules, allows substances to dissolve easily

Front 7

Other key properties of water:

Back 7

- High specific heat (can store heat)

- High latent heat of vaporisation (takes a lot of energy for phase change)

- High density

Front 8

Comparing thermal properties of water and methane

Back 8

Front 9

Water (heat transport)

Back 9

- Plasma is 55% of blood and composed of 92% water
- Heat can be transferred from one part of body to another through blood

Front 10

Water (habitat)

Back 10

- High specific heat

- Takes a long time to heat up or cool large bodies of water, making it stable

Front 11

Water (coolant)

Back 11

- High specific heat and latent heat of vaporization

- Evaporation causes hydrogen bonds to break apart, using energy

- Sweat allows cooling as heat energy is expended to break H-bonds

Front 12

Water (transport in plants)

Back 12

- Adhesion: water molecules attracted to surface of xylem vessel wall, creates high adhesion forces

- Cohesion: water molecules evaporate from surface of a leaf cell, others are pulled from behind creating a transpiration stream

Front 13

Monosaccharides (3)

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- Glucose
- Fructose
- Galactose

Front 14

Disaccharides (3)

Back 14

- Maltose (glucose x2)

- Lactose (glucose + galactose)

- Sucrose (glucose + fructose)

Front 15

Draw Ribose

Back 15

Front 16

Alpha-D-glucose and Beta-D-glucose

Back 16

Front 17

Polysaccharides

Back 17

More than two monosaccharides joined to form a chain: starch, cellulose, glycogen

Front 18

Cellulose structure

Back 18

- beta-D-glucose

- 1-4 linkage

- Unbranched, straight chains

- Very strong due to cross-linkages by hydrogen bonding

Front 19

Starch structure

Back 19

- alpha-D-glucose

- 1-4 linkage

- Two forms: amylose and amylopectin

- Amylose unbranched

- Amylopectin is slightly branched: 1-6 linkages

- Both forms coiled and insoluble

Front 20

Glycogen structure

Back 20

- alpha-D-glucose

- 1-4 linkage

- Profusely branched: 1-6 linkages

- Insoluble

Front 21

Cellulose function

Back 21

- Cell wall: support, structure, protection

- Porous, allows water through

Front 22

Starch function

Back 22

- Energy storage in plants

- Both forms found together in starch grains

Front 23

Glycogen function

Back 23

- Energy storage in animals

- Stored in liver, skeletal muscle cells

- Forms granules in cytoplasm

Front 24

Lipids (3)

Back 24

- Triglycerides

- Phospholipids

- Steriods

Front 25

Triglyceride structure

Back 25

Glycerol + three fatty acids, formed by condensation

Front 26

Fatty acids: structure, types

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- Saturated: no double bonds, more energy

- Unsaturated: one or more double bonds (mono + poly unsaturated)

Front 27

Cis vs. Trans

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- Cis: Hydrogen atoms on the same side of the double bond, come in omega-3 and omega-6

- Trans: Hydrogen atoms on opposite sides, partially or fully hydrogenated

Front 28

Phospholipids

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- Modified triglyceride

- Third fatty acid replaced with phosphate group

- Make the molecule polar

Front 29

Steroids

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- Three 6-sided rings, one 5-sided ring

- Functional (F) group can be attached to 5-sided ring

Front 30

Carbohydrates as energy stores

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- 17 kJ per gram

- Easily built up and broken down

- Glycogen in animals, starch in plants: convert to glucose when energy is required

Front 31

Lipids as energy stores

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- 38 kJ per gram

- More efficient because lipids are hydrophobic and less mass is taken up storing water

- Break down more slowly

- Converted into fatty acids and glycerol and then into Acetyl-CoA

Front 32

LDL & HDL

Back 32

- Low and high density lipoprotein, transport molecules for lipids

- LDLs referred to as 'bad' cholesterol, HDLs 'good' cholesterol

Front 33

Condensation and hydrolysis in carbohydrates (draw)

Back 33

Front 34

Condensation and hydrolysis in lipids (draw)

Back 34

Front 35

Condensation and hydrolysis in amino acids (draw)

Back 35

Front 36

Residue

Back 36

Part of monomer lost during formation of a di/polymer