BIOL 213 Chapters 5, 6, 7, 4

Quizlet for Exam 2 material

Federick Grifffith

Who showed that heat-killed infectious bacteria can transform harmless live bacteria into pathogens in the 1920s. The S strain (smooth) killed the mice, while the R strain lived on. The heat-killed S strain and injected it, mouse then lives. When mouse is injected with living R strain & heat-killed S strain, the mouse died. Hypothesized that mouse would live. However, transformation occurred and the mice died from the S strain infection.

In vivo

in a living model or aka:

S strain

What strain killed the mice?

DNA

Avery, MacLeod, and McCarty demonstrated that ____ was the transforming principle and the genetic material. (Mid 1940s)

Avery, MacLeod, McCarty; DNase; DNA

Who used enzymes to break down certain classes of molecules from S strain cells? Which enzyme resulted in an R strain cell or live mouse? When enzymes weren’t used to break down the molecules, which molecule, when put into the solution of R strain cells, caused a S strain cell or killed the mouse?

Chargaff’s Rule

What rule is A = T, G = C?

Hershey and Chase

Who took DNA labeled with 32p and Protein labeled with 35s into a solution of bacteria and then sheared off the viral heads from the bacteria, and then centrifuged, resulting in 32p infected bacteria but not 35s? The more dense was found in the bottom and was radioactive phosphor was in the bacteria and the radioactive sulfur was above in the liquid.

Antibiotic resistance

What can viruses help reverse with by attaching to a bacteria cell’s pump?

Watson and Crick; Rosalind Franklin

Used molecular models based on x-ray diffraction data from _______ _______ and Maurice Wilkins to propose a double helix structure for DNA where the bases were A-T and G-C pairs.

right-handed turn; Z

Most of the time DNA is _____. A-form is more condensed while B-form is less condensed and is most common. A left-handed turn is considered a __-form.

Hydrogen bonds

What exists between bases that contributes to helical stability?

the base pairs have identical widths

Why is the helix diameter uniform in widths?

Major and Minor grooves

What are important sites for DNA/protein interactions?

complementary

nucleotides on one chain are _______ to nucleotides on the other strand.

G and C; 3 hydrogen bonds

Which base pairing is harder to break? Why?

Phosphodiester bond

how are nucleotide subunits within a DNA strand are held together?

T, C

(Name the nucleoside closest to it) Which end is the 5’ and which end is the 3’?

3’; 5’

The OH end is the ___. The Phosphate end is the ___.

32P; in the cells at the bottom

What was used to label the DNA in Hershey and Chase’s experiment? Where was this found in the container?

3’

What end of a DNA strand do new nucleotides add to?

2

How many hydrogen bonds do an A & T pairing make?

nucleotides

What are subunits of nucleic acids?

nucleotide

A _______ consist of a nitrogen-containing base, a five-carbon sugar, and one or more phosphate groups.

Double Helix

Implications of DNA being a ____ _____. linear arrangement of nucleotides could store genetic information and complementarity provided mechanisms for replication of it.

protein

The only genes that get transcribed into mRNA make _____.

A, B, D; noncoding RNA

Which of these genes produce mRNA? What would RNA C be called?

noncoding RNA

What is RNA that doesn’t produce a protein called?

3.4 billion base pairs

How big is the human genome?

polyploid

Carry multiple copies of the same genome

diploid

carry 2 copies of the same genome. (chromosomes in pairs)

haploid

carry 1 copy of the same genome

false

True or False: the more chromosomes, the bigger the genome.

Eukaryotes

________ have chromosomes that are very long, single DNA molecules associated with proteins that fold and pack it.

chromatin

The complex of DNA and associated proteins is called….

chromatid

A _____ is the structure of the part of the chromosome during cell division.

homologous

______ chromosomes in a pair that are very similar but not necessarily identical.

FISH

provides researchers with a way to visualize and map the genetic material in an individual’s cells, including specific genes or portions of genes.

GISH

a technique that allows distinguishing the genomes in a cell.

end of them

Where are the telemores located on the chromosome?

middle

Where is the centromere located?

duplicate

During interphase, the chromosomes ______.

During M-phase the chromosomes____.

metaphase

Which has more condensed chromosomes, metaphase or interphase?

A, E, D, B, C

Order these from least dense to most dense:

A) DNA strand

B) looped domains

C) chromatid

D) 30nm fiber

E) Nucleosome

nucleosomes

What are the basic units of eukaryotic chromatin structure?

cohesin

what makes the physical loops, all interphase?

condensin

What makes loops on loops before cell division?

false

True or false: Bacteria have nucleosomes

clamp protein interactions

What stops further looping?

euchromatin

loosely packed transcriptionally active DNA

heterochromatin

densely packed inactive DNA (shows up dark under a microscope)

replication origin

nucleotide sequence where DNA replication begins.

heterochromatin

chemical modification is required for what to be produced?

remodeling complex B

causes the dissociation (removal) of DNA-binding protein resulting in restoration of standard nucleosomes

remodeling complex A

allows for the addition of DNA-binding proteins

euchromatin

chromatin remodeling complexes alter chromatin structure in __________.

H1

which histone provides additional packaging of nucleosomes in the chromatin fiber?

SMC Ring complex

uses the energy of ATP hydrolysis to motor along the DNA, pushing out a loop of DNA in its wake

during mitosis

When are chromosomes in their most compact form?

positively, negatively

Histone proteins have a high proportion of __________ charged amino acids, which bind tightly to the ________ charged DNA backbone.

methylation

powerful gene silencer/repressor (can form heterochromatin) causes tightening of packing.

acetylation

gene promoter causing loosening of the packing trumps all when it is found at lysine 9

long, short

trimethyl groups are usually ____ term while single methyls are usually ______ term.

phosphorylation

neutralizes the positive charge on histones which loosens the packing (other than acetylation)

lysine 9

which is the most important (and commonly) protein on a histone tail to be modified to alter gene expression?

trimethyl

most common form of modification for long term heterochromatin

phosphorylation and acetylation

What is found together on a commonly used gene?

Histone 3

which histone can be modified?

methylation

DNA can also be modified by _________.

x inactivation

one or other of the two X chromosomes in each nucleus becomes highly condensed into heterochromatin early in embryonic development. Thereafter, the condensed and inactive state of that X chromosome is inherited in all of the many descendants of those cells. responsible for calico (tortoise shell) cats.

bar body

the x chromosome that is inactive and condensed

The co-color genes for cats are on the X chromosome. The cell that is chosen will have a designated x activation pattern which is why the clone has one color vs two. The bar body is maintained as heterochromatin structure.

Why are calico cats an unusual choice for a cloning experiment? How does chromatin alteration fit in?

somatic

Cloning involves an _______ cell.

imprinting

a gene is turned off in the father and also turned off in the offspring

DNA replication

Process of producing two identical replicas from one original DNA molecule

false

True or false: only one strand of the double stranded DNA can be used as a template for the synthesis of a new complementary strand.

semi-conservative

Original parent strand is separated, each new strand is half original, half synthesized

dispersive

initially chopped the DNA which led to each strand containing new and original strands.

conservative

the parent strands stay together while the newly synthesized DNA is together.

Meselson-Stahl

Whose experiment is this describing?

Parent production using 15N and 14N with 15N created a band at the bottom of the tube due to its high density and 14N created a band at the top due to its low density. After this, they put the solution of the parent 15N in a solution of 14N to create strands that were half N14 and half N15 an intermediate band was created from this. After this, they did the replication once more which led to a strands that were completely N14 or half N14 and half N15.

N15

Which is heavier N15 or N14?

DNA is semi-conservative

What was the conclusion of the Meselson-Stahl experiment?

100% N14

What would be shown at the end of the Meselson-Stahl experiment if DNA was dispersive?

Initiator proteins, replication origins

What protein begins the DNA synthesis and what are the DNA sequences they are bind to called?

initiator proteins

the ______ _____ pry the two DNA strands apart, (denature) breaking the hydrogen bonds between the bases. they can readily unzip short regions of the double helix at normal temperatures. They keep DNA strands separated.

one; 1 for every 3000bp

How many origins of replications do bacterias have? How about humans?

replication forks

DNA molecules in the process of being replicated contain Y-shaped junctions. What are these called?

A-T; 2 hydrogen bonds

Replication origins are more likely to be A-T or G-C rich? Why?

bidirectional

DNA replication in both eukaryotes and prokaryotes are considered _______ because the replication forks have two replication machines moving in opposite directions.

5, 3

DNA synthesis always proceeds from the ___’ to the ____’

DNA polymerase

what enzyme catalyzes the addition of nucleotides by forming phosphodiester bonds to the 3ʹ end of a growing DNA strand, using one of the original, parent DNA strands as a template?

pyrophosphate; 2 phosphates; irreversible

What molecule is released by the polymerization reaction? What does this molecule get hydrolyzed to? Why is this significant? (hint it makes this reaction _______>

helicase

the “unzipper”. Breaks the hydrogen bonds at each replication fork.

Leading strand

the new 5’ to 3’ strand formed

Okazaki fragments

the fragments of 3’ to 5’ strand

DNA polymerase

proof reads strand from 3’ to 5’ and makes new strand 5’ to 3’. Can only add nucleotides to the 3’ end.

Draw the leading and lagging strands in a replication fork. Make sure the leading strand is showing where nucleotides are being added to.

RNA; primers; primase

short length of ____ serve as _____ for DNA synthesis used by DNA polymerize as a template. They are synthesized by the enzyme _______.

Draw out the DNA replication process with the enzymes and label everything of importance

topoisomerase

This enzyme creates a single stranded break in the double helix structure to relax the coiling of the Double stranded DNA