WEEK 1

Question 1

prokaryotes

Answer 1

single celled, no nuclei, includes eubacteria and archea (also called bacteria and arcbacteria)

Question 2

eukaryotes

Answer 2

have nuclei, can be single or multicellular, includes plants, funghi, animals, humans

Question 3

Example of a single celled eukaryote

Answer 3

yeast

Question 4

Features of the prokaryotic cell

Answer 4

capsule - polysaccharide layer for protection from engulfment (optional)
cell wall - tough, protective outer coat (optional)
plasma membranes - surrounds all cells
DNA nucleoid - compact structure of DNA (NO NUCLEUS, but is still found in specific part of cell)

Question 5

Which features are optional in prokaryotic cell (which ones are not present in all p. cells)?

Answer 5

Capsule and cell wall, flagellum and pilus

Question 6

Ribosome

Answer 6

protein synthesis

Question 7

flagellum

Answer 7

locomotion (not in all prokaryotes)

Question 8

Pilus

Answer 8

two types:

• one for locomotion
• one for sexual conjugation

Question 9

Eukaryotic cell

Answer 9

• 1000 times bigger than prokaryotic cell, which means it requires cytoskeleton for support
• has membrane bound organelles
• has mitochondria (powerhouse of cell, ATP generation)
• has nucleus
• has plasma membrane like prokaryotic

Question 10

Features that plant cells have but animal cells don’t…

Answer 10

cell wall - for protection
chloroplast - for photosynthesis
vacuole - two types for storage and degradation (there are similar structures in animal cells but they’re called something else)

Question 11

Two lines of evidence that show eukaryotes evolved from prokaryotes

Answer 11

fossil record - eukaryotes appear in record 1 billion years later after prokaryotes
structural similarity - share many complex traits that could not have evolved independently

Question 12

Endosymbiont Theory

Answer 12

• Eukaryotic ancestor is a heterotrophic (cannot produce own food must take organic matter from environment) anaerobic (derived energy from food matter without molecular oxygen) cell
• mitochondrial ancestor was a free living, aerobic prokaryote able to use oxygen to help generate ATP that was engulfed by the larger heterotrophic aerobic cell and resisted digestion in cytoplasm

Question 13

FECA

Answer 13

First Eukaryotic Common Ancestor

• gave shelter to mitochondrial ancestors in exchange for oxygen generated ATP
• nuclear membrane developed as symbiosis occurred

Question 14

LECA

Answer 14

Last Eukaryotic Common Ancestor

- does not contain chloroplasts (last common ancestor between us and plants)

Question 15

What was the key step in producing FECA?

Answer 15

Prokaryotic ancestors somehow acquired ability to form internal membranes and compartments. The key step towards FECA was the development of these membranes into closed internal compartments (which then allowed for production of nucleus to hold DNA).

Question 16

Are internal membranes exclusively a eukaryotic trait?

Answer 16

No, some bacteria can have extensive internal membrane networks but they are NOT closed—they do not have membrane bound organelles like eukaryotes

Question 17

Evidence for endosymbiont theory

Answer 17

1. Some prokaryotes form simple internal membranes
2. There are carnivorous single-celled eukaryotes which can phagocytosize (engulf) things - shows that the mechanism is plausible
3. Mitochondria and chloroplast still have evidence of their own DNA - genome is circular and looks prokaryotic
4. Both mitochondria and chloroplast have double membranes and their own ribosomes (remnant structures)

Question 18

Where did Margulis propose chloroplasts came from?

Answer 18

Cyanobacteria. An early heterotrophic eukaryote acquired ability to photosynthesize.

Question 19

Archea are prokaryotes but are in some ways…

Answer 19

more similar to eukaryotes.

Question 20

How does the double membrane of mitochondria and chloroplast provide evidence for endosymbiont theory?

Answer 20

The internal and external membrane have different compositions. Possible that one originated from original anaerobic host cell and other from the host cell itself.

Question 21

Cyanobacteria, Methanococcus, Methanobacteria

Answer 21

• capable of photosynthesis (PROKARYOTE)
• lives at hydrothermal vents at bottom of ocean (ARCHEA)
• lives in low pH, anaerobic conditions (cow stomach) (ARCHEA)

Question 22

Difference between 19th/20th century method and 20th/21st century method of studying diversity?

Answer 22

Older approaches - collect more stuff and organize

Newer approaches - model organisms

Question 23

Model organisms

Answer 23

• studied extensively over a long period of time
• have rapid development with short life cycles
• small adult size (can fit in lab)
• readily available
• tractability (ease of modification/manipulation)
• understandable genetics (DNA is not too complicated)

Question 24

Central dogma

Answer 24

DNA –(transcription)–> RNA —-(translation)–> PROTEIN

Question 25

How is the central dogma slightly more complicated

Answer 25

There are many different types of RNAs some of which have nothing to do with making proteins and even STOP you from making proteins.

Question 26

Types of RNAs

Answer 26

mRNA - messenger RNA, codes for proteins tRNA - transports amino acids, used in protein synthesis rRNA - part of the ribosome

Question 27

Genome

Answer 27

complete set of DNA sequences in a cell or organism

Question 28

Transcriptome

Answer 28

complete set of RNA sequences in a cell or organism

Question 29

Proteome

Answer 29

complete set of proteins in a cell or organism

Question 30

Interactome

Answer 30

complete set of protein interactions in a cell/organism

Question 31

Metabolome

Answer 31

complete set of small, molecule metabolites in a cell/organism (deals with nutrients and wastes (ATPS, lipids, etc)).

Question 32

Phenome

Answer 32

complete set of phenotypes for the cell/organism

Question 33

Brief summary of steps in protein synthesis in eukaryotes

Answer 33

- segment of DNA is transcribed (RNA is made) - mRNA processing - nuclear export (goes into cytoplasm) - translation - protein folding

Question 34

DNA

Answer 34

Deoxyribonucleic acid

Question 35

RNA

Answer 35

Ribonucleic acid

Question 36

Components of DNA and RNA? What's the difference between the two?

Answer 36

1. Pentose sugar 2. nitrogenous bases (varies) 3. Phosphate group (backbone) DNA is missing the hydroxyl group on the 2' carbon (IT STILL HAS OXYGEN)

Question 37

Where does the carbon numbering start on the ring?

Answer 37

Outside on the carbon that attaches to the phosphate group — that one is the 5'. The base attaches to the 1'

Question 38

Purines

Answer 38

Guanine and Adenine | - have two rings

Question 39

Pyramidines

Answer 39

Cytosine, Uracil, Thymine | - each only has one ring

Question 40

interactions between molecules...

Answer 40

are usually noncovalent interactions

Question 41

nucleotide

Answer 41

nucleoside with phosphates—can be monophosphate, diphosphate, triphosphate. A nuceloside is just a sugar and a base covalently bonded.

Question 42

Common component of all amino acids

Answer 42

An alpha carbon that has a carboxyl group, an amino group, and an R group attached

Question 43

Number of naturally existing amino acids

Answer 43

20

Question 44

What differentiates between amino acids?

Answer 44

R groups

Question 45

What part of the amino acid is NOT involved in peptide bond formation?

Answer 45

The R group

Question 46

How are peptide bonds formed?

Answer 46

Carboxyl reacts amino to form water and strong covalent peptide bond. The peptide bond exists between the carbon of the carboxyl group and the nitrogen of the amino group of the other amino acid. OH from carbxyl and proton from amino form water.

Question 47

What kind of reaction is peptide bond formation?

Answer 47

Condensation (also known as dehydration synthesis)

Question 48

More amino acids are added onto...

Answer 48

carboxyl end (c-terminus) until AA chain is complete

Question 49

What are amino acids in a polypeptide chain called?

Answer 49

Residues

Question 50

What structure does the polypeptide chain form?

Answer 50

twists in on itself to form cylindrical structure because of hydrogen bonding between oxygen of carbonyl group on residue "n" and the hydrogen of amine group on residue n+4 (ex. 1 and 5, 2 and 6, 3 and 7, 4 and 8, etc). Because the h-bonding only occurs every 5 residues, the structure doesn't appear until the chain is at LEAST 5 residues.

Question 51

What stabilizes the alpha helix?

Answer 51

hydrogen bonds between carbonyl oxygen and amine group

Question 52

Difference between Thymine and Uracil?

Answer 52

One of the hydrogens on Uracil is replaced with a methyl group in Thymine.