Lecture 2

Question 1

Molecules of life

Answer 1

Water

Macromolecules

Question 2

What is the solvent of life

And why

Answer 2

Water

Dissolves more molecules than any other solvent

It’s a polar molecule (opposite charge on each end)

Dissolves polar and charged molecules

Question 3

What are the macromolecules

Answer 3

Carbohydrate
Lipids
Protein
Nucleus acids

Question 4

Polymers of sugars

Answer 4

Carbohydrates

Question 5

What macronutrient isn’t a polymer

Answer 5

Lipid

Question 6

Polymers of amino acids

Answer 6

Proteins

Question 7

Polymers of nucleotides

Answer 7

Nucleus acids

Question 8

Polymers

Answer 8

Chains composed of molecules called monomers

Polymerize and depolymerize

Question 9

Polymerization

Answer 9

Go from a monomer to a polymer

Question 10

Depolymerization

Answer 10

Go from polymer to monomer

Question 11

Polymerization/ depolymerization reactions often involve loss or addition of what

Answer 11

Water

Therefor can also be described as

Dehydration synthesis(polymerization)

Hydrolysis (depolymerization)

Question 12

Another word for polymerization

Answer 12

Dehydration synthesis

*Synthesis means making (making polymer from monomer)

Question 13

Another word for depolymerization

Answer 13

Hydrolysis

Question 14

Where does addition or loss of water happen in polymerization and depolymerization

Answer 14

Happens at the binds between monomers

Known as condensation polymerization

Question 15

Enzymes

Answer 15

Catalyze the synthesis/ hydrolysis of polymers

Question 16

What Catalyze the synthesis/ hydrolysis of polymers

Answer 16

Enzymes

Question 17

enzymes in synthesis/ hydrolysis of polymer

Answer 17

Polymerases

Hydrolases

Question 18

-ase suffix =?

Answer 18

Enzyme

Question 19

What do biopolymers look like

Answer 19

They’re not simple chains

-twist and fold up
-chains arrange into varied levels of higher order structure

Examples: DNA double helix + protein folding

Question 20

Higher order polymer structure example- proteins

Answer 20

1° structure- amino acids chain

2° structure- ex. Helix or a sheet

3° structure- folding

4° structure- assembling with other proteins into a complex

Question 21

What determines a proteins structure

Answer 21

Properties and order of the amino acids

Question 22

Amino acids

Answer 22

Contain nitrogen

Mildly acidic

R= sidechain

Sidechain properties define the chemistry of proteins

Question 23

Amino acids are linked by

Answer 23

Covalent bonds called peptide bonds

Question 24

Protein AKA

Answer 24

Polypeptides

Question 25

How many different amino acids

Answer 25

20

Question 26

What causes polypeptides to twist or form sheets

Answer 26

Hydrogen bonds between nearby amino acids

Question 27

Protein twist name

Answer 27

Alpha helix

Question 28

Protein sheet name

Answer 28

Beta sheets

Question 29

Tertiary protein structure

Answer 29

Chemistry between side chains causes higher-order folding

Question 30

Quaternary protein structure

Answer 30

Individual proteins interact to form complexes Again determined by their structure and chemistry

Question 31

Why was/is protein structure hard to predict

Answer 31

A- Central dogma of molecular biology means that for any gene we know exactly what amino acids will make up the protein B- it’s HARD to predict what it will look like C- it took years using X-ray crystallography to identify protein shape D- machine learning: alpha gold and other ML based computer programs

Question 32

Cell theory

Answer 32

1-All organisms are composed of one or more cells 2- cell is the basic structural and functional unit of all living organisms 3- cells arise only from the division of pre-existing cells

Question 33

When were cells first observed

Answer 33

1600s

Question 34

Robert Hooke

Answer 34

1600s Looked at cork cells

Question 35

Anton van Leeuwenhoek

Answer 35

Made a better microscope than Hooke and saw animacules Animacules*

Question 36

Why are cells small

Answer 36

- Surface area must be sufficient to allow exchange of stuff between the cell and its surroundings - larger volumes require more surface area to achieve this - larger volumes need more structural support

Question 37

Trade off between cell surface area and volume

Answer 37

As volume increases, Surface area doesn’t increase proportionally Ex. In a cube V= a cubed A= 6a squared Volume is way higher the larger a gets

Question 38

What if cells need a large surface area

Answer 38

They develop convoluted/ branch surface morphologies Ex- brain cells, leaf epidermal cells, microvilli on intestinal epithelial cells

Question 39

What if cells need a larger volume

Answer 39

They use cell walls Example- xylem vessels from wood

Question 40

Resolution- microscope

Answer 40

Ability of a microscope to distinguish 2 objects as being no separate

Question 41

Higher magnification increases

Answer 41

Resolution

Question 42

Higher contrast gives

Answer 42

More detail but can’t increase resolution

Question 43

Microscopy types

Answer 43

Light microscopy Electron microscopy

Question 44

Light microscopy types

Answer 44

Reflected light Transmitted light Fluorescence

Question 45

Electron microscopy types

Answer 45

Transmission Scanning

Question 46

Relflected light microscopy

Answer 46

- stereo microscope (aka dissecting microscope) - lighting from top - can see bigger size cells

Question 47

Transmitted light

Answer 47

- stereoscopes (some can also use light from the bottom) - compound microscopes

Question 48

Variations on transmitted light compound

Answer 48

1- brightfield 2- darkfield 3- phase-contrast 4- DIC (differential interference contrast aka. Nomarksi) 2-4 are: - contrast enhancing methods - exploit refractive (light scattering) properties of specimens - variations in specimen thickness and density influence how light passes through it

Question 49

Brightfield

Answer 49

Ones we use in the lab Staining of term required to see more details

Question 50

Contrast enhancing methods

Answer 50

Darkfield Phase contrast Differential interference contrast (DIC/ nomarski)

Question 51

Dark field

Answer 51

- illuminates sample at an angle so light does not hit the objective lens directly - only light that is scattered upwards by the sample reaches the objective lens

Question 52

Phase contrast

Answer 52

This method creates slight phase shifts in the illuminating light, which manifest as higher detailed images

Question 53

DIC

Answer 53

Differential interference contrast - similar to phase contrast - gives a pseudo 3D appearance