Molecular Genetics Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

How many nitrogenous bases are there?

A

4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the backbone made out of in DNA?

A

Phosphate and Sugar

it repeats

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Bases are bonded to..

A

sugars, not directly the phosphate.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

The sugar in DNA is..

A

deoxyribose = 5 carbon sugar (pentose sugar)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Chargaff’s Rule

A

amount of A = T
amount of C = G

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Nucleotides

A

sugar, phosphate, and one base

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Purines and Pyrimidines

A

Purines - A and G = 2 rings
Pyrimidines - C and T = 1 ring

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Double Helix

A
  • the shape of dna
  • two strands parallel to each other
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Types of bonds in DNA

A

Hydrogen bonds between bases
Covalent bonds between sugar and phosphate

G and C are triple hydrogen bonded, A ant T are double hydrogen bonded

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

The enzymes involved in DNA replication

A

DNA helicase - seperates the two stands
DNA polymerase - adds new nucleotides to the unzipped original DNA molecule
DNA ligase - seals the new nucleotides into place.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

DNA is replicated in a..

A

semi-conservative matter
which means that each new DNA molecule has one orginal and new strand

DNA replcation occurs in the nucleus.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

DNA vs RNA

A
  • RNA has ribose sugar instead of deoxyribose
  • RNA has uracil instead of thymine
  • RNA is a single stranded structure.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Types of RNA

A

mRNA - carries the coding sequence for protein synthesis
tRNA - molecules carries the anticodons to the ribosomes and decodes the mRNA into a protein
rRNA - makes up the structure of ribosomes. made in the nucleolus but shipped to the cytoplasm.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Transcription

A

occurs in the nucleus of eukaryotes and cytoplasm of prokaryotes
one of the DNA strands is used as a template to make RNA.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

RNA Polymerase

A

binds to DNA and seperates the two stands, and one of the strands is used as a template for making RNA.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Promoter and Terminiation Site

A
  • a region of DNA where the RNA polymerase attaches and where it starts transcription.
  • a region of DNA where the RNA polymerase detattaches and where transcription ends.
17
Q

Translation - what do ribosomes do?

A

the site of where protein synthesis takes place

18
Q

Codons vs Anticodons

A

codons - a sequnce of three nucleotides in mRNA that determines the position of amino acids.
anti-codons - a sequence of three nucleotides in tRNA that have an opposite sequence that matches specific codons, they binds to mRNA and designate that amino acid.

19
Q

Genetic Code

A

the instructions in a gene that tell a cell how to make a specific protein

20
Q

Start and Stop codons

A
  • there are specific codons that start the translation process
    (AUG)
  • there are specific codons that end the translation process
    (UAG, UGA, UAA)
21
Q

Importance of redundant genetic code

A
  • minimizes the harmful effects that incorrectly placed nucleotides have on protein synthesis
    (because the third letter can be changed without changing the amino acid.)
22
Q

Why is the genetic code 3 bases per codon?

A

we need 20 amino acids but 4^2 is only 16, but 14^3 is 64 which is why we have wobble letters.

23
Q

Code is..

A

Universal, DNA of different species can be combined together.

24
Q

Chromosomal Mutations involve…

A

more than one gene

25
Q

Chromosomal Mutations

may invole change in structure or loss of part of structure.

A

deletion - a piece of chromosome is lost

inversion - a piece of chromosme break off and flips around backward, the segment then reattaches.

translocation - involves two chromosomes that aren’t homologous, part of one chromosome is transferred to the other.

duplication - gene sequence is repeated

nondisjuction - failure of chromosomes to seperate during mitosis, may cause too many or too few chromosomes.

26
Q

Gene Mutations involve..

A

one gene!

change in the nucleotide sequence of a gene

26
Q

Point Mutations

A
  • change of a single nucleotide
  • includes the deletion, insertion, or
    substitution of ONE nucleotide in a gene
  • results in frameshift mutation which changes the rest of the nucleotides are the change in the single nucleotides.
26
Q

Silent, Nonsense, and Missense Mutations

A

silent - substituting a base does NOT change the amino acid
nonsense - substituation leads to a STOP codon
missense - substitution leads to a change in amino acid

26
Q

What mutations can be passed to offspring?

A

mutations in the gametes/sperm cells (least common)

mutations in the somatic cells cannot be passed to offspring (most common)