DNA Chromosomes & Genomes I Flashcards Preview

Molecular Biology > DNA Chromosomes & Genomes I > Flashcards

Flashcards in DNA Chromosomes & Genomes I Deck (31):
1

What happens to the chemical structure of a gene when it is passed from a cell to daughter cell?

It is mostly uchanged.

2

In the 19th century, it was found that chromsomes contain DNA and protein in ___ amounts.

Equal

3

In a study, S strain cells were fractionated into classes of purified molecules. All of the molecules produced S strain cells except for DNA. What can be concluded from this?

The molecule that carries the heritable information is DNA.

4

What is found at the 5' end of DNA?

Phosphoryl end

5

What is found at the 3' end of DNA?

Hydroxyl end

6

How are sugars and bases linked?

Covalently via glycosidic bonds.

7

Are DNA strands arranged parallel or anitparallel?

Antiparallel.

Each strand's sequence is complementary to the parter.

8

What are the purines?

Adenine and guanine

9

What are the pyrimidines?

Cytosine and thymine

10

How many hydrogen bonds are found between adenine and thymine?

2

11

How many hydrogen bonds are found between guanine and cytosine?

3

12

What is a genome?

A complete set of information in an organism's DNA.

The entire genome must be duplicated and passed to the daughter cell.

13

Each human cell contains ___ copies of each chromosome

2

14

In humans, there are __ paies of autosomes and __ sex chromosomes

22 pairs of autosomes

2 sex chromosomes

15

When do translocations commonly occur?

During an abnormal recombination event.

16

Translocations commonly occur during abnormal events, such as cancer. Translocation can also be useful for what purpose?

Maintaining the correct amount of genetic material

17

What are genes?

The information-containing elements that determine the characteristics of a species.

18

Does condensation of chromosomes occur during interphase or mitosis?

Mitosis

19

What are three chromosome requirements?

DNA replication origin

Centromere

Telomeres

20

What DNA binding proteins are involved in forming chromosomes?

Histones and non-histone chromosomal proteins.

21

What makes up chromatin?

Proteins and nuclear DNA.

22

What is the most basic unit of chromosome packing?

The nucleosome

23

How is DNA digested?

It is digested by nucleases. It cuts between nucleosomes and degrades exposed DNA between nucleosome core particles.

24

How many proteins are found in each individual nucleosome?

8

25

What are histones?

Small proteins with a hisone fold. They are what DNA wraps around.

They also have an N terminal amino acid tail that extends out from the core and are subject to covalent modifications important for chromatin regulation.

26

What type of bond hods DNA and histones together?

Hydrogen bonds

27

What is the purpose of chromatin remodeling complexes?

They allow loosening of DNA/histone contact.

28

The structure of the nucleosome is temporarily changed in chromatin remodeling. What is the consequence of this?

DNA is less tightly bound to the histone.

29

What is the zig-zag model?

A model in which histones are condensed into a pattern via a zig-zag fashion.

30

What is a primary function of histone tails?

They help to condense chromatin. They are largely unstructured, suggesting they are highly flexible.

The tails can also form interactions with adjacent nucleosomes.

31

What is histone H1?

A linker histone that contacts both DNA and protein. It changes the path of the DNA as it exits the nucleosome.