Uvic Biol 225 Midterm 1

Front 1

What does cytology focus on?

Back 1

Focuses on cellular structure and uses optical techniques

Front 2

Biochemistry focus: ?

Back 2

Focuses on cellular function

Front 3

Genetics focus : ?

Back 3

Focuses on information flow and genetics

Front 4

What are two tools used by cytologists? (3)

Back 4

•Themicrotome-- Allows the preparation of very thin slices of samples

•A variety of dyesand the development of immunohistochemistrytechniques -- Stain cells or cell compartments/molecules

•The smaller the limit of resolutiona microscope has, the greater its resolvingpower

Front 5

electron microscope stats:

Back 5

resolving power 0.1-0.2 nm

100 000x magnification

Front 6

Tools used in Biochemistry (3):

Back 6

•RadioactiveIsotopes-- to trace the fate of specific atoms and molecules

•Subcellularfractionation -- suchas centrifugationto separate/isolate different structures and macromolecules

•Ultracentrifuges--capable of very high speeds (over 100,000 revolutions per minute)

Front 7

Tools used in Biochem pt.2 (3):

Back 7

•Chromatography--Separates molecules from a solution based on size, charge, or chemical affinity••Electrophoresis--Uses an electrical field to move proteins, DNA or RNA molecules through amedium based on size/charge••MassSpectrometry --Determines the size and composition of individual proteins

Front 8

Origin of genetics? Chromosone Theory of genetics come from this work

Back 8

Gregor Mendel's Pea experiment in 1866. Described hereditary factors. Now known as genes.

- Chromosome Theory of Genetics would come from his work and others

Front 9

Each gene is responsible for : ?

Back 9

A single protein

Front 10

Who proposed the DNA double helix?

Back 10

Watson and Crick in 1953

Front 11

What are two tools used in genetics that Separates DNA and RNA molecules: ?

Back 11

Ultracentrifugation and electrophoresis

Front 12

What is a tool used in genetics that Uses the ability of nucleic acid bases to bind to each other?

Back 12

Nucleic acid hybridization

Front 13

What is the technology used in genetics that uses Restriction enzymes to cut DNA at specific places forming recombinant DNA molecules,with DNA from different sources?

Back 13

Recombinant DNA technology

Front 14

What is a tool used in genetics to rapidly determine the base sequencesof DNA molecules?

Back 14

DNA sequencing

Front 15

In vitro is?

Back 15

•using purified chemicals and cellular components

Front 16

In vivo is?

Back 16

•using live cells or organisms

Front 17

Insilico is ?

Back 17

• using computer analysis of largeamounts of data

Front 18

Define Hypothesis

Back 18

statement consistent with most of the data, may take the form of a model(an explanation that appears to account for the data); must be testable

Front 19

Define a Theory:

Back 19

a hypothesis that has been extensivelytested by many investigators, using different approaches, widely accepted

Front 20

Define a Law:

Back 20

•atheory that has been tested and confirmed over a long period of time withvirtually no doubt of its validity

Front 21

Lecture 2. The Chemistry of the cell.

Back 21

YAY!

Front 22

What are the five principles of Cell biology?

Back 22

--Characteristics of carbon and water.

-Selectively permeable membranes

–Synthesis by polymerization of small molecules

Self Assembly

Front 23

Which 5 other atoms is carbon most likely to bind to ?

Back 23

PHONS.

Front 24

What is stability expressed as?

Back 24

Bond energy - theamount of energy required to break 1 mole (~6x 1023) of bonds

Front 25

•Bond energy is expressed as caloriesper mole (cal/mol)•Acalorie isthe amount of energy needed to raise the temperature of 1g of water by 1oC

Back 25

:P

Front 26

Which functional groups are negatively charged?

Back 26

Carboxyl and phosphate

Front 27

Which are positively?

Back 27

amino

Front 28

Which are (uncharged;but polar) ?

Back 28

Hydroxyl, sulfhydroxyl, carbonyl, aldehyde

Front 29

What is a configurational stereoisomer?

Back 29

A non superimposable mirror image ( chiral)

Front 30

A compound with nasymmetric carbons willhave how many possible stereoisomers?

Back 30

2^n. Each asym C has two possible stereoisomers.

Front 31

What is responsible for the high:

Surfacetension, Boilingpoint and Heatof vaporization of water?

Back 31

The extensive network of Hydrogen bonding

Front 32

How does water absorb so much heat with little change in temperature?

Back 32

Heat is absorbed by breaking the many hydrogen bonds

Front 33

What is heat of Vaporization?

Back 33

•the amount of energy required to convert one gram of liquid into vapor

Front 34

The high heat of vaporization of water makes it an excellent solvent for cells. Why?

Back 34

B/c it protects proteins in solution from overheating

Front 35

How do water molecules reduce the chances of re-association between dissolved ions?

Back 35

They form spheres of hydration around the ions

Front 36

Cell membrane consists of ? (3) + 3

Back 36

phospholipids, glycolipids and membrane proteins.

Also sterols. cholesterol in animals

•ergosterols (fungi), or phytosterols (plants)

Front 37

What are the main 3 types of membrane proteins?

Back 37

Transport

Enzyme

Receptor

Front 38

Are membranes permeable to polar or nonpolar molecules?

Back 38

Non polar because of the hydrophobic interiors

Front 39

Why are even the smallest of Ions still unable to diffuse across the bilayer?

Back 39

Because of their charge and the surrounding hydration shell.

Front 40

Consider revising types of transports proteins. 7 in total

Back 40

:P

Front 41

In the polymerization of monomers, monomers must first be _______ before condensation can occur?

Back 41

activated. Once activated it is in a higher energy state, and it consumes this energy during condensation sythesis

Front 42

How does a monomer become activated?

Back 42

Is must be coupled with a carrier molecule

Front 43

Does this process use ATP?

Back 43

Yes, or an alternative high E molec.

Front 44

Remember that the carrier molecule is removed after condensation.

Back 44

:P

Front 45

What is the carrier molecule of protein synthesis?

Back 45

tRNA

Front 46

What is the carrier molecule of Polysaccharide synthesis?

Back 46

sugars (monomer) are often activated by linking them with ADP and UDP.

Front 47

What is the carrier molecule of Nucleic Acid synthesis?

Back 47

–nucleotides themselves are high-energymolecules (ATP, GTP)

Front 48

Assisted self-assembly has what?

Back 48

molecular chaperones

Front 49

What class are many chaperones a part of ?

Back 49

Heat shock

Front 50

What are two advantages to heirarchical self assembly, in terms of simplicity and efficiency?

Back 50

relatively few subunits are used for a wide variety of structures

a small number of condensation reactions are needed

Front 51

What is another advantage in terms of quality control?

Back 51

Early mistakes can be repaired or omitted before being incorporated into larger structures

Front 52

There are 8 types of proteins. The follow are the less obvious ones

Back 52

Lets get em

Front 53

Structural Proteins

Back 53

-- physical support and shape (e.g., cytoskeletal proteins)

Front 54

Motility Proteins

Back 54

-- contraction and movement (e.g., muscle proteins: myosin & actin)

Front 55

Regulatory Proteins

Back 55

control and coordinate cell function (e.g., cell signaling, cell death, gene transcription/repression)

Front 56

Transport Proteins

Back 56

move substances in and out of cells (e.g., membrane transporters and channels)

Front 57

Communication Proteins

Back 57

communication between cells (e.g., hormones, neurotransmitters)

Front 58

Receptor Proteins

Back 58

enable cells to respond to chemical stimuli from the environment

Front 59

Defensive Proteins

Back 59

Defensive Proteins

Front 60

Storage proteins -

Back 60

reservoirs of amino acids

Front 61

All proteins are made from the same 20 amino acids. But some do not. What is this the result of?

Back 61

Modification

Front 62

9 AA have unpolar hydrophobic groups

Front 63

What are the two acidic AAs?

Back 63

Aspartate and glutamate

Asp and Glu

GluAsp

Front 64

What are the three basic AAs?

Back 64

Lys Arg and His

LAH

Front 65

Describe a peptide bond?

Back 65

C-N covelent bond b/w two AAs

Front 66

Two cystein residues may form which type of bond?

Back 66

covalent disulfide bonds

Front 67

How are the formed?

Back 67

With the removal of two hydrogens. (Oxidation)

Front 68

Are these bonds intermolecular

Back 68

Yes, but also intramolecular

Front 69

Polypeptides form in which direction?

Back 69

N-terminus --> C-terminus

Front 70

Which bonds and forces maintain quaternary structure?

Back 70

The same as tertiary.

H bond

van der waals

ionic

hydrophobic

covalent (s-s)

Front 71

What are the two Purine bases?

Back 71

Adenine and guanosine

A and G

Front 72

What are the Pyrmidines?

Back 72

Thymine, cytosine and uracil

Front 73

What is a sugar base portion of DNA?

Back 73

A nucleoside

Front 74

A nucleside + ________ = nucleotide?

Back 74

Phosphate

Front 75

What is the difference in the sugar b/w DNA and RNA?

Back 75

DNA 2' C-H

RNA 2' C-OH

Front 76

Adenine forms __ H-bonds with __?

Back 76

2,Thymine

Uracil if RNA

Front 77

Cytosine forms __H-bonds with ___ ?

Back 77

3 H - bonds with Guanine

Front 78

Polysaccharides consist of ____ repeating unit(s)

Back 78

1 sometimes two in alternating fashion

Front 79

What is the most common sugar?

Back 79

aldohexose. D-glucose, which is the most stable stereoisomer

Front 80

In the cell does D-glucose exist as a ring?

Back 80

No. It exists in an equilibrium b/w linear and ring form.

Fisher projection shows linear form and makes aldehyde obvious

Front 81

How is alpha D glucose defined?

Back 81

In alpha D glucose the 1 C OH group is downwards

Front 82

How is beta D glucose defined?

Back 82

In beta D glucose the 1C OH group is upwards

Front 83

What type of bond links disaccharides?

Back 83

glycosidic bonds (with the elimination of water)

Front 84

Glycosidic bonds involving A-D-glucose are called glycosidic bonds

Back 84

Glycosidic bonds involving B-D-glucose are called B glycosidic bonds

Front 85

if a A-D-glucose bonds with a B-D-Fructose, what type of bond will form?

Back 85

an A-glycosidic bond

Front 86

The most common storage polysaccharide in animals is?

Back 86

glycogen

Front 87

The most common storage polysaccharide in plants is ?

Back 87

Starch

Front 88

How would one describe the bonding of starch and glycogen ?

Back 88

A 1-->4 glycosidic

With branching at A(1--->6)

Front 89

How often does glycogen branching occur?

Back 89

Every 8-10 glucose units

Front 90

Where is glycogen stored in animals?

Back 90

In liver, for glucose, and in muscle as a fuel source for muscle contraction

Front 91

In what two forms does starch occur?

Back 91

As branched (every 12-25 glucoses) Amylopectin (70-90%) and amylose (10-30%)

Front 92

Where is starch stored?

Back 92

In the plastids as starch grains. In amyloplasts and in chloroplats

Front 93

What is the compositon of cellulose?

Back 93

B-D-Glucose

Front 94

Bacterial cell walls contain which two kinds of sugars?

Back 94

GlcNAc (N-acetylglucosamine) and MurNAc (N-acetylmuramic acid)

Front 95

And they are derivatives of what?

Back 95

B-glucosamine,

Front 96

Linked alternately with what type of bond?

Back 96

B(1--->4)

Front 97

What is chitin's composition?

Back 97

GlcNAc, B (1--->4)

Front 98

Polysaccharide Structure Depends on the Type of Glycosidic Bonds Involved

Back 98

Sure does.

Front 99

A-glycosidic are loose

Back 99

B-glycosidic are rigid linear rods that aggregate into microfibrils, about 5-20 nm in diameter

Front 100

Lipids

Back 100

yay!

Front 101

What are 3 functions of lipids?

Back 101

energy storage, membrane structure and signal transmission

Front 102

few polar groups, but some are amphipathic, with polar and nonpolar regions

Back 102

ya

Front 103

There are 6 classes of lipids

Back 103

un mas

Front 104

What is the structure of a fatty acid?

Back 104

Long unbranched hydrocarbon with a carboxyl group at one end

Front 105

12 to 20 carbonsEven numbers of carbons are favored because fatty acid synthesis occurs via the stepwise addition of two-carbon units

Back 105

Fatty acids are highly reduced and generate a large amount of energy upon oxidation

Front 106

What are 2 functions of triaglycerols?

Back 106

Energy storage and insullation

Front 107

Animals triacylglycerols are semi solid at room temp

Back 107

Plant TGCs are fluids. They are predominantly unsaturated fatty acids

Front 108

What are two types of phospholipids?

Back 108

Phosphoglycerides and sphingolipids

Front 109

Draw a phosphatic acid. Which is the backbone of phosphoglycerides, which are the predominant phospholipid in membranes

Back 109

2 fatty acids and a phosphate group attached to a glycerol

Front 110

The R group is usually serine, ethanolamine, choline, or inositol, which contributes to the polar nature of the phospholipid head group

Back 110

Usually have 1 sat and 1 unsat tail

Front 111

Where are sphingolipids found?

Back 111

On the outer leaflet of the plasma membrane

Front 112

What are glycolipids?

Back 112

Lipids with a carbohydrate group instead of a phosphate group

Front 113

What are they derived from?

Back 113

Glycerol and sphingosine

Front 114

Carb group 1-6 sugars long

Back 114

Occur largely on the outer monolayer of the plasma membrane

Front 115

What is the base structure of steroids?

Back 115

tetracyclic hydrocarbon

Front 116

Are they polar?

Back 116

No, they arn't

Front 117

How do they differ from one another?

Back 117

Functional groups and location of double bonds

Front 118

Whats the most common steroid in animals?

Back 118

Cholesterol, it plays a large role in membrane fluidity

Front 119

What is cholesterol the precursor of?

Back 119

Steroid hormones. Such as M and F sex hormones, glucocorticoids and mineralcorticoids

Front 120

What are estrogens and androgens?

Back 120

Female SH and male SH

Front 121

What do glucocorticoids do?

Back 121

they promote glucosneogenesis and reduce inflammation

Front 122

What do mineralcorticoids do?

Back 122

They promote reabsorption of HCO3-, Na, and Cl by the kidneys

Front 123

What are terpenes synthesised from?

Back 123

Isoprene, a 5 C compound

Front 124

Terpenes and its derivatives are joined in various combinations to produce substances such as____?

Back 124

Vitamin A and Cartenoid pigments

Front 125

While archaea and bacteria are both prokaryotes, rRNA sequence analysis reveals how widely divergent archaea are from bacteria

Back 125

:P

Front 126

Where are archaea commonly found?

Back 126

In extreme condition where they have developed diverse metabolic strategies

Front 127

What are methanogens?

Back 127

Archaea who get energy from H2 and convert CO2 into methane

Front 128

What are Halophiles

Back 128

Archaea who occupy extremly salty environments

Front 129

What are Thermacidophiles?

Back 129

Archaea who live in acidic hot springs

Front 130

Archaea emerged from a common ancestor of eukaryotes long after diverging from bbacteria

Back 130

ya!

Front 131

Cells are small because?

Back 131

Beyond a certain threshold they would not be able to take in enough nutrients and release enough wastes

Front 132

Many molecules rely on diffusion to move around the cell. Larger molecules have a slower rate of diffusion.

Back 132

>.>

Front 133

What are some steps cells take to avoid the limitations of diffusion?

Back 133

Carrier proteins to actively transport materials through the cytoplasm.

And vesicles transported along microtubules

Front 134

Cells must also stay small because of the necessity to maintain adequate reactant and enzyme concentrations, so as to maintain a high level of collisions b/w reactants and enzymes

Back 134

yay!

Front 135

As cell size increases the number of molecules must increase proportionate to__________?

Back 135

Cell volume, which grows a lot

Front 136

How do organelles avoid the issue of concentraions?

Back 136

They are specialized compartments for specific functions

Front 137

The nucleolus, which is a distinguishing feature of eukaryotes from prokaryotes, also is the site of what synthesis and assembly?

Back 137

rRNA synthesis and ribosome assembly

Front 138

Eukaryotes have a nuclear membrane, which has 2 membranes.

How is bacterial DNA arranged?

Back 138

the genetic information is folded into a compact structure called the nucleoid and is attached to the cell membrane

Front 139

How is bacterial DNA organized?

Back 139

Circular with few protein interactions

Front 140

How is EUK DNA organized?

Back 140

linear and complexed with large amount of histones

Front 141

How is Archaea DNA organized

Back 141

circular and complexes with proteins similar to EUK histones

Front 142

Bacterial and Archaeal cell duplicate their DNA and divide by ________?

Back 142

binar fission

Front 143

Eukaryotic cells replicate DNA and distribute their chromosomes into daughter cells by mitosis & meiosis, followed by cytokinesis, division of the cytoplasm

Back 143

:PPP

Front 144

This type of cell transcribes genetic information into RNA, and each RNA molecule may contain information for several polypeptides.

What type is it ?

Back 144

Bacterial

Front 145

RNA molecules become involved in protein synthesis before transcription is complete.

What type of cell does this?

Back 145

Archaea and Bacteria

Front 146

CMMMMembrane !

Back 146

woop woop

Front 147

What type of proteins would the cytoskelton connect to in the plasma membrane?

Back 147

Anchor Proteins

Front 148

Nucleopores are lined with what complex?

Back 148

nuclear pore

Front 149

When are chromosomes most visible?

Back 149

During mitosis

Front 150

When are chromosomes least visible? and what form are they in during said phase

Back 150

During interphase when they are dispersed as chromatin

Front 151

Mitochondria contain small circular molecules of DNA, which encodes some RNAs & proteins needed for mitochondrial function

Back 151

yup

Front 152

Mitochondria also have their own_________ to carry out protein synthesis?

Back 152

ribosomes

Front 153

How is ATP produced in the mitochondria?

Back 153

By the oxidation of sugars and other fuel

Front 154

What are the cristae of the mitochondria?

Back 154

infoldings of the inner mitochondrial membrane

Front 155

What is the mitochondrial matrix?

Back 155

The fluid that fills the inside of the mitochondrion

Front 156

Where are most proteins of the mitochondria localized?

Back 156

The cristae and the matrix

Front 157

Tissues with high demand for ATP have many mitochondria, located within the cell at the site of greatest energy needsE.g.: sperm cells

Back 157

---------_-_-_> also e.g. muscle cells

Front 158

Chloroplasts and Mitochondria are surrounded by both ________ and ____________ membranes?

Back 158

inner and outer

Front 159

Chloroplasts contain a system of __________ that are stacked into __________

Back 159

thylakoids stacked into grana

Front 160

In or on thylakoid membranes are the site of what reactions?

Back 160

Solar energy dependant reactions

Front 161

Reactions involved in the reduction of CO2 to sugar occur within the__________

Back 161

stroma, which is asemifluid in the interior of the chloroplast

Front 162

Chloroplasts also reduce NO3- from soils into __________
(hint: is it needed for protein synthesis)

Back 162

NH3

Front 163

Chloroplast function is the reverse of mitochondrial reactions that __________ glucose into CO2

Back 163

oxidize

Front 164

How do chloroplasts relate to mitochondria?

Back 164

They have a small amount of circular DNA which codes for a few of their own ribosomes and proteins
DNA not associated with histones

Front 165

The inner membrane of MIT and CHLO has what type of lipids?

Back 165

Bacterial lipids

Front 166

tubular membranes and flattened sacs of the ER are called what?

Back 166

cisternae

Front 167

The internal space of the ER is the

Back 167

lumen

Front 168

The ER is continuous with other parts of the cell

Back 168

OK!

Front 169

The RER is studded with _____________ and their role is ____________?

Back 169

ribosomes that synthesize polypeptides

Front 170

Where do those polypeptides go?

Back 170

Either the accumulate in the membrane or are transported to the lumen

Front 171

What is the role of the SER

Back 171

Lipids synthesis e.g. cholesterol and its derivatives

Front 172

It is also responsible for __________ and ___________ harmful substances?

Back 172

deactivating and detoxifying

Front 173

Sarcoplasmic reticulum does what ?

Back 173

sequesters Ca2+ ions critical for contraction tissues

Front 174

What is the main function of the GA ?

Back 174

processing & packaging secretory & membrane proteins

Front 175

What is another, similar role of the GA?

Back 175

complex polysaccharide synthesis

Front 176

It also accepts __________ that bud off from the _________

Back 176

vesicles

ER

Front 177

Secretory and membrane proteins are often glycosylated. Where does this occur?

Back 177

It begins in the ER and then is completed in the GA

Front 178

How do these processed materials move to other parts of the cell?

Back 178

In vesicles that bud off the GA

Front 179

Exocytosis releases contents into the ECM

Back 179

hey ho

Front 180

What are the 4 components that constitute the endomembrane system, which trafficks substances through the cell

Back 180

ER, GA, vesicles and lysosomes

Front 181

What do lysosomes store?

Back 181

Hydrolases

Front 182

What are hydrolases?

Back 182

enzymes that can digest any kind of biological molecule

Front 183

How is the lysosome protected from the hydrolases that it sequesters?

Back 183

A special carbohydrate coating

Front 184

How is H2O2, a harmful by-product of cellular respiration managed within the cell?

Back 184

H202 is converted into H20 and 02 by catalse enzyme which is present in peroxisomes

Front 185

What else do peroxisomes do?

(hint: related to SER)

Back 185

detoxify toxins

Front 186

Where in the body are peroxisomes found in high concentration?

Back 186

Liver and kidneys

Front 187

What is the role of vacuoles in animal and yeast cells?

Back 187

Temporary storage or transport

Front 188

A phagosome is the result of __________?

Back 188

phagocytosis

Front 189

If a phagosome (vacuole) fuses with a lysosome its contents are _____________to provide _____________ for the cell

Back 189

hydrolyzed

nutrients

Front 190

Why are ribosomes not organelles?

Back 190

B/c they are not enclosed by a membrane

Front 191

They are found in all cells but differ in bacteria, archaea and eukarya in their size & composition

Back 191

nice

Front 192

EUK cell ribosome sediment coefficients are approx ?

Back 192

60s and 40s

Front 193

50s and 30s in _________ and ___________ ?

Back 193

Bacteria and Archaea

Front 194

Other than structural support, what are 3 roles of the cytoskeleton?

Back 194

Cell division

Cell movement

Intracellular transport

Front 195

What are the largest structural elements of the cytoskeleton

Back 195

microtubules

Front 196

mitotic spindle fibers and axoneme of cilia are both _____________ based structures?

Back 196

microtubule

Front 197

draw and label a microtubule and its monomers

Back 197

do it
Atub+Btub= tubulin dimer --> protofilament
--> microtubule

Front 198

What are the smallest components of the cytoskeleton

Back 198

microfilaments?

Front 199

What is the monomer of mircofilaments?

Back 199

Actin

Front 200

Draw and label a microfilament and its monomers

Back 200

Microfilaments Are polymers of the protein actin

Actin is synthesized as a monomer called G-actin (globular)

These subunits are polymerized into F-actin (filamentous), with a helical appearance

G-actin ---> F-actin ----> Microfilament

Front 201

These filaments are the most stable and least soluble. What are they?

Back 201

Intermediate filaments

Front 202

Where are they found

Back 202

Areas of mechanical stress such as muscle cells

Front 203

There are six classes of intermediate filaments and animal cells from different tissues can be distinguished on the basis of the types of intermediate filament proteins they contain

Back 203

just stop

Front 204

Animal cell ECM consists of _______ fibers and ___________

Back 204

collagen and proteoglycans

Front 205

What is role of proteoglycans?

Back 205

They confer mobility and elasticity

Front 206

What does the primary cell wall consist mainly of ?

Back 206

Cellulose fibrils embedded in a polysaccharide matrix

Front 207

Secondary Cell Wall: Formed once the cell reaches its final size & shape by ?

Back 207

deposition of additional cellulose and pectin on the inner surface of the primary cell wall

Front 208

How are plant cells connected?

Back 208

Plasmodesmata

Front 209

How large molecules can pass through plasmodesmata?

Back 209

H2O and small solutes

Front 210

How do animal cells communicate?

Back 210

Gap junctions.

Tight and adhesion jctns also connect animal cells

Front 211

Viruses are noncellular parasitic particles incapable of _________________________?

Back 211

Free living existence

Front 212

consist of only a few different molecules of____________?

Back 212

nucleic acid and protein

Front 213

they use invaded cells' machinery to produce more virus particles

Back 213

uh oh

Front 214

Viruses consist of a ____________ (protein coat) that encapsulates a core containing _______ and ______

Back 214

capsid

DNA

RNA

Front 215

Enveloped viruses are ones that _________

Back 215

are surrounded by a membrane

Front 216

Viruses have no ________, _________ and can only reproduce via the machinery of other cells

Back 216

metabolism

irritability ( ability to perceive and respond to outside stimuli)

Front 217

Asymetric carbons allow for the formation of ________ which are mirror images of eachother

Back 217

configurational stereoisomers

Front 218

Which of thefollowing can only be viewed by electron microscopy? A) Frog eggs B) Viruses C) Nuclei D) Mitochondria E) Bacteria

Back 218

B)