LEC EXAM #2 CHP. 10

Question 1

Biofilm: (3)

Answer 1

• Growth of bacteria/fungi on a surface
• Composed of polysaccharides, nucleic acids, proteins, and lipids
• Allows for formation of water channels to provide shelter, protection, hydration, and nutrients to cells

Question 2

Bacterial cells secrete:

Answer 2

A gel-like extracellular substance that allows for good attachment to a surface and passage of water channels

Question 3

Benefit of water channels passing through:

Answer 3

Can send signals to other bacterial cells that nutrients are present

Question 4

Bacterial growth through binary fission:

Answer 4

Bacteria duplicates DNA->grows->splits into 2 cells

Question 5

Septum:

Answer 5

Used to build new cell wall off of for the next cell

Question 6

Gregor Mendel:

Answer 6

• Father of modern genetics
• Bread pea plants
• Observed characteristics of genes being passed from parents to progeny (vertical gene transfer)

Question 7

Binary fission is:

Answer 7

Asexual reproduction

Question 8

Chromosomal genes of inheritance:

Answer 8

DNA contains certain segments that contain specific genes

Question 9

Hammerling’s contribution:

Answer 9

• Importance of how DNA functions
• Indirect
• Mushroom Experiment: Took am a mushroom and cut off the head-> head regenerated DT the nucleus being at the foot of the mushroom

Question 10

Griffith experiment:

Original belief?

Answer 10

• 1st experiment to determine what genetic info is made of
• Indirect
• Originally they thought amino acids were our DNA because we have 20 amino acids and 4 nucleotides in DNA-> more amino acids than DNA variations

Question 11

How did Griffith experiment work?

Answer 11

2 strains of pneumoniae:

• virulent strain: causes disease (smooth strain)
• avirulent strain: non-disease causing (rough strain)

Question 12

Why is virulent strain smooth?

Answer 12

In a capsule for protection against getting engulfed and abx treatment

Question 13

Griffith exp.

• Smooth inject mouse->
• Rough inject mouse->
• Heat smooth inject mouse->
• Heat smooth + rough inject mouse->

Answer 13

Dies
Lives
Lives
Dies

Question 14

Why does the mouse die when you heat the smooth and add it to rough then inject the mouse?

Answer 14

Because DNA doesn’t die with heat-> genes for capsule from smooth is passed onto R-> builds a capsule through transcription and translation-> mouse dies-> recovers live S

Question 15

During his experiments, Griffith only knew:

Answer 15

That R got transformed into S

Question 16

Avery experiment contribution:

Answer 16

• Practiced extension of Griffith’s experiments

- Indirect

Question 17

How did Avery’s experiments work? (3)

Answer 17

1. Heated S-> adds RNAase (eats RNA)-> adds live R-> injects mouse-> mouse dies + live S
2. Heated S-> adds protease (eats protein)-> adds live R-> injects mouse-> mouse dies + live S
3. Heated S-> adds DNAase (eats DNA)-> adds live R-> injects mouse-> mouse lives + no live S

Question 18

In Avery experiments, why did the mouse live when adding DNAase to heated S?

Answer 18

Because when DNAase eats DNA, this gets rid of the gene to make a capsule-> can’t go through transcription or translaton-> R can’t transform into S

Question 19

Hershey and Chase experiment:

Answer 19

• Directly tests if DNA is genetic info
• Phages infected host cells with DNA and protein-> DNA (Phosphorus-32) found inside cells and protein (Sulfur-35) found outside cell

Question 20

How was the Beadle and Tatum experiment performed?

Answer 20

Starts with fungal spores that are treated in 2 different ways:
A. 1 left alone
B. 1 with x-ray on it-> causes mutations to spores

Question 21

Mutation of DNA causes:

Answer 21

Mutation of a gene that’s important for synthesis of a particular protein/amino acid

Question 22

Significance of Beadle and Tatum’s experiment:

Answer 22

Showed when pieces of DNA are mutated, it caused direct effect on the proteins needed for growth

Question 23

Structure of deoxyribose nucleotide:

Answer 23

Sugar- deoxyribose (no O2)
Phosphate
Nitrogenous base

Question 24

Purines

Answer 24

• Double rings
• bigger structure
• adenine + guanine

Question 25

Pyrimidines

Answer 25

-Single rings -small structure -cytosine + thymine (both have Y's)

Question 26

How do we link nucleotides together?

Answer 26

Phosphodiester bond

Question 27

What is off of your 3' carbon?

Answer 27

OH | -Attacked by incoming nucleotide's phosphate-> phosphate creates covalent bond with OH (phosphodiester bond)

Question 28

You ALWAYS add to:

Answer 28

a free 3' hydroxyl

Question 29

Synthesis of DNA goes:

Answer 29

5' phosphate to 3' hydroxyl

Question 30

5' reacts with 3' to:

Answer 30

Create a phosphodiester bond

Question 31

You CANNOT add onto:

Answer 31

a free 5' phosphate

Question 32

A -> T have:

Answer 32

2 hydrogen bonds

Question 33

C -> G have:

Answer 33

3 hydrogen bonds

Question 34

Twist make bonds:

Answer 34

More stable

Question 35

Heating causes:

Answer 35

Bonds to break apart but won't break individual strains apart

Question 36

How does deoxyribonucleotide differ from a ribonucleotide?

Answer 36

H for DNA | OH for RNA

Question 37

RNA does not have:

Answer 37

A complementary strand because RNA is single stranded

Question 38

DNA vs. RNA:

Answer 38

DNA - deoxyribose - thymine instead of uracil - double stranded RNA - ribose - uracil instead of thymine - single stranded - complementary strand to template DNA

Question 39

Process of making mRNA:

Answer 39

Transcription

Question 40

Process that happens between DNA-> mRNA:

Answer 40

Transcription

Question 41

Process that happens between mRNA-> protein:

Answer 41

Translation

Question 42

tRNA used to:

Answer 42

Link together correct amino acids

Question 43

tRNA structure:

Answer 43

- unique piece of RNA - only double stranded RNA molecule - has an amino acid attached to its 3' hydroxyl end - at the other end it has 3 bases that are complementary to mRNA strand

Question 44

Once tRNA hydrogen bonds with mRNA:

Answer 44

The correct amino acid is on the other end

Question 45

Codon:

Answer 45

3 base pairs on mRNA that codes for an amino acid

Question 46

Anti-codon:

Answer 46

Complimentary tRNA to codon

Question 47

Gene:

Answer 47

Segment of DNA that codes for a protein

Question 48

Non-coding region of DNA is important for:

Answer 48

Chromosomal structure/integrity

Question 49

Telomerase:

Answer 49

- Enzyme that rebuilds telomere | - Rebuilds the chewed up portion that the DNAase eats

Question 50

Telomeres:

Answer 50

- on ends of chromosomes - non-coding (no genes) - prevents genes from getting eaten

Question 51

Kineticore:

Answer 51

Group of proteins that binds mitotic spindle + centromere

Question 52

Centromere:

Answer 52

- Non-coding region - Important for structural movement of chromosomes - Middle DNA of chromosome

Question 53

Genotype vs. phenotype:

Answer 53

- Genotype doesn't change | - Phenotype changes due to temperature

Question 54

How do organize our DNA?

Answer 54

- Nucleosome: DNA wraps around 8 histone protein octomer that has tails that have positive charges - Phosphate on DNA has negative charge so DNA has negative charge

Question 55

Nucleosome:

Answer 55

-DNA + histone octamer

Question 56

First level of impaction: | Second level of impaction:

Answer 56

Nucleosome | Solenoid

Question 57

6 octamer/nucleosomes=

Answer 57

Solenoid

Question 58

Human DNA structure vs. bacterial DNA:

Answer 58

Humans have linear DNA | Bacteria have circular DNA + plasmids

Question 59

Quorum sensing:

Answer 59

- Is how biofilm communicate with each other or change gene expression - Causes upregulation of gene expression

Question 60

Plasmids:

Answer 60

- Extra pieces of DNA inside bacterial cell | - Can replicate independently

Question 61

How to transfer plasmids to other bacterial cells?

Answer 61

Pilus

Question 62

Exponential/log phase:

Answer 62

- Adjusts their gene expression to the nutrients available and grow rapidly until the nutrients are depleted - 99% of bacteria we use

Question 63

Lag phase:

Answer 63

- Uptaking gene and changing gene expression | - No increase in bacterial cell growth yet because they are still getting used to/acclimated to the environment

Question 64

Good biofilm vs. bad biofilm:

Answer 64

Good: on gut and respiratory lining Bad: formation on teeth, plaque