Biology 108 Quiz 1

Chemistry and Structure of Life

isotopes

atoms of an element can differ in number of neutrons

How many bonds does hydrogen have?

1

How many bonds does oxygen have?

2

How many bonds does sulfur have?

2

How many bonds does nitrogen have?

3

How many bonds does carbon have?

4

How many bonds does phosphorus have?

5

carbon atoms are

tetrahedral

Three ways to draw organic molecules

all atoms, all bonds except for hydrogens, all carbons missing (implied) + no hydrogens attached to carbon

How to determine the # of hydrogens attached to a carbon

Count # of lines (= bonds) at each vertex and the # of hydrogens is 4- bonds to carbon

Functional Groups

Hydroxyl, Aldehyde, Keto, Carboxylate, Amino, Phosphate,

sulfhydryl

Type of Compound + Functional Group

Alcohols, Hydroxyl

Type of Compound + Functional Group

Aldehydes, Aldehyde

Type of Compound + Functional Group

Ketones, Keto

Type of Compound + Functional Group

Carboxylate, Carboxylate

Type of Compound + Functional Group

Amine, Amino

Type of Compound + Functional Group

Thiol, Sulfhydryl

Type of Compound + Functional Group

Organic Phosphates, Phosphate

Electronegativity

attractive force that the nucleus exerts on its electrons

Negative Charge tendency

O, N, CL

Neutral Charge Tendency

H, C, P, S

Positive Charge Tendency

Na, K

With Polar Bonds: O or N are usually bonded to

H, S, C, P

Coulomic is a

non-covalent interaction

cations

positive ion

anions

negative ion

Hydrogens that do not form hydrogen bonds example

amino acids

Coulombic charge to charge interactions

ionic bonds and hydrogen bonds are qualitatively similar ionic positive charge with negative charge

polar is synonyms with

hydrophilic

hydrophilic

water-loving

polar

H-bonds with water

non-polar is synonyms with

hydrophobic

hydrophobic

water-hating

non-polar

not forming h-bonds with water

non-polar substances tend to __ in water

coalesce

coalesce

cluster

hydraphobic effect

when non-polar substances cluster in water

example of hydraphobic effect

oil and water/dressing

Why do the hydrophobic molecules coalesce in water

to maximize strong water-water interactions. To minimize weak water-oil interactions

hydrophobic molecules are a more ___ when coalesce in water

energetically favorable structure

hydrophobic interactions are driven by

maximizing strong water-water interactions

van de Waals interactions

induced dipoles and are greatest when shapes are complimenting

Synonyms for Sugar

carbohydrate and saccharide

sugar is a

macromolecule

monomer form of sugar

Cn(H2O)n, n needs to be greater than 3 total carbons to be considered a sugar

purposes for sugar

energy, metabolic intermediates, structural, other

6 carbon sugar vs 5 carbon sugar

6 carbon is a hexose like glucose while 5 carbon is a pentose like ribose

Most sugar named molecules end in

“ose”

Glucose has multiple forms

straight chain, then a beta-D-glucose or a alpha-D-glucose

straight chain glucose is __ % of forms found in nature

0\.02%

Beta-D-glucose is __% of forms found in nature

66%

Alpha-D-glucose is __% of forms found in nature

34%

straight chain ring closure

In a straight chain carbon 5 hydrogen reactions with carbon 1 oxygen to create a ring

this is

ring closure of straight sugar chain

this is

Beta-D-Glucose (ring form)

this is

Alpha-D-Glucose (ring form)

types of sugar polymers

disaccharides, oligosaccharide, polysaccharide

Disaccharides example is

glucose + fructose → sucrose

this is an example of _ and a _ reaction

disaccharides, dehydration

oligosaccharide can have

3-20 monomers

polysaccharide can have

from 3-thousands of monomers

examples of polysaccharides

cellulose: plants linear structural, starch: plants branched sugar storage, glycogen: animals highly branched sugar storage

Types of Lipids

fatty acids, triglycerides, phospholipids

Types of fatty lipids

saturated, unsaturated

Saturated fatty lipids

solid at room temperature found in animals, example is lard

this is

saturated fatty lipid

the saturated fatty lipid is not _ , the tail/head of the saturated fatty lipid is _ while the rest of the chain is _

kinked, polar/hydrophilic, non-polar/hydrophobic

this is

unsaturated fatty lipid

the unsaturated fatty lipid is _, it requires to have _ , and it is not __

kinked, one or more double bonds with carbon, packed tightly

example of unsaturated fatty acid in nature

at room temp appears as oils (in plants) like palm oil

Triglycerides are

a lipid

ester bond is a

functional group

ester bond

a bond between (acid + alcohol) called fats and oils

triglycerides are a set of

three fatty acids lined up like spoons put on top of each other

this is a _ reaction with __

dehydrate reaction, H2O

the triglycerides after the dehydration reaction with H2O is

largely hydrophobic

phospholipids

a glycerol molecule with two fatty acids and one nonpolar/hydrophobic attached to a phosphate which is attached to an organic amine. The phosphate and organic amine is polar/hydrophilic

phospholipids form

bilayers

this is

phospholipid bilayer

large bilayers form

vesicles

large bilayers forming vesicles explains

how cells are developed by phospholipids. Proteins are found on the surface of cells and can interact with phospholipds

Fluid Mosaic Model of membranes

membranes are mostly phospholipids, which move transversely in its layer but does not flip between layers

this is the

fluid mosaic model

Lipid rafts

“float” in the membrane and contain special lipids to which proteins bind

example of special lipids in lipid rafts

sphingomyelin and cholesterol

sphingomyelin represents a

phospholipid who’s head sticks out and the non-polar tail embeds in the membrane

cholesterol represents a

smaller molecule who’s head is lower but is within the same polar region as the phospholipid head and embeds in the membrane

3 types of proteins in membranes

integral, anchored, peripheral

intergral membrane protein

fits through the bilayer, which is called transmembrane protein

anchored membrane protein

has a covalently attached lipid, which inserts into the membrane

peripheral membrane protein

interacts with either membrane surface or integral protein or anchored protein

the circles with yellow indicate the

peripheral membrane protein

the red circle indicates the

integral membrane protein

the blue circle indicates the

anchored membrane protein

Cells interact __ requires cell-cell recognition

adhesion

cell uniqueness established by unique cell surface components results in unique cell types like

glycolipids, glycoproteins

glycolipids

carbohydrates covalently linked to lipid

glycoproteins

carbohydrates linked to a membrane

glycolipids and glycoproteins help

cells recognize each other’s individual characteristics such as liver cells versus stomach cells

cell-cell contacts (3 types)

tight junctions, desmosomes, gap junctions