Intro 1_Molecular_Biology_Flashcards

Question 1

What is molecular biology?

Answer 1

The study of macromolecules and their mechanisms in living organisms.

Question 2

What are the key focuses of molecular biology?

Answer 2

Molecular nature of genes, gene replication, mutation, and gene expression.

Question 3

What is the central dogma?

Answer 3

Genetic information flows from DNA to RNA to protein.

Question 4

What are the two key processes in the central dogma?

Answer 4

Transcription (DNA to RNA) and Translation (RNA to protein).

Question 5

Who explained the central dogma and emphasized the one-way flow of information?

Answer 5

Francis Crick.

Question 6

When did molecular biology emerge?

Answer 6

In the 1930s and 1940s.

Question 7

Who first identified DNA and what was it called?

Answer 7

Friedrich Miescher, called it ‘nuclein’.

Question 8

Who coined the term ‘molecular biology’?

Answer 8

Warren Weaver in 1938.

Question 9

What did Chargaff’s rules state?

Answer 9

Ratios of A to T and G to C are equal in DNA.

Question 10

What major discovery did Watson and Crick make in 1953?

Answer 10

The double helical structure of DNA.

Question 11

Who discovered mRNA?

Answer 11

Francois Jacob and Jacques Monod in 1961.

Question 12

What did Francis Crick decipher in 1961?

Answer 12

The triplet codon pattern.

Question 13

What are the three components of DNA?

Answer 13

Deoxyribose sugar, phosphate group, and nitrogenous bases.

Question 14

What are the four nitrogenous bases in DNA?

Answer 14

Adenine (A), Thymine (T), Cytosine (C), Guanine (G).

Question 15

What pairs with A in DNA, and how many bonds?

Answer 15

Thymine (T) with 2 hydrogen bonds.

Question 16

What pairs with C in DNA, and how many bonds?

Answer 16

Guanine (G) with 3 hydrogen bonds.

Question 17

What is the orientation of DNA strands?

Answer 17

Antiparallel (5’ to 3’ and 3’ to 5’).

Question 18

What stabilizes DNA?

Answer 18

Hydrogen bonds, base stacking interactions, and hydrophobic interactions.

Question 19

Is DNA soluble in water?

Answer 19

Yes, due to hydrophilic phosphate groups.

Question 20

At what wavelength does DNA absorb UV light?

Answer 20

260 nm.

Question 21

What is DNA denaturation?

Answer 21

Separation of double strands into single strands by heat or extreme pH.

Question 22

What is renaturation?

Answer 22

Rejoining of DNA strands when conditions return to normal.

Question 23

What is the melting temperature (Tm) of DNA?

Answer 23

The temperature at which half of the DNA is denatured.

Question 24

Why is DNA negatively charged?

Answer 24

Due to phosphate groups in its backbone.

Question 25

How is DNA packaged in the nucleus?

Answer 25

Using histones to form nucleosomes.

Question 26

Where is mitochondrial DNA located?

Answer 26

Inside mitochondria.

Question 27

What is the shape of mtDNA?

Answer 27

Circular, double-stranded.

Question 28

How many genes does mtDNA contain?

Answer 28

37 genes (2 rRNAs, 22 tRNAs, and 13 for proteins).

Question 29

How does mtDNA replicate?

Answer 29

Independently of nuclear DNA.

Question 30

What is the shape of nuclear DNA?

Answer 30

Linear double helix.

Question 31

What is the shape of mitochondrial and bacterial DNA?

Answer 31

Circular.

Question 32

Is histone association present in nuclear DNA?

Answer 32

Yes, but absent in mitochondrial and bacterial DNA.

Question 33

How is mitochondrial DNA inherited?

Answer 33

Maternally.

Question 34

Where is eukaryotic DNA located?

Answer 34

In the nucleus.

Question 35

Where is prokaryotic DNA located?

Answer 35

In the cytoplasm.

Question 36

Are plasmids present in eukaryotic DNA?

Answer 36

No, but often present in prokaryotic DNA.

Question 37

Are introns present in eukaryotic DNA?

Answer 37

Usually, but absent in prokaryotic DNA.

Question 38

What is a nucleotide?

Answer 38

A molecule consisting of a sugar, phosphate group, and nitrogenous base.

Question 39

What is a nucleoside?

Answer 39

A nucleotide without a phosphate group.

Question 40

What are purines?

Answer 40

Double-ring bases (A and G).

Question 41

What are pyrimidines?

Answer 41

Single-ring bases (C, T, and U).

Question 42

What bonds link nucleotides in DNA?

Answer 42

Phosphodiester bonds.

Question 43

Where does transcription occur?

Answer 43

In the nucleus.

Question 44

Where does translation occur?

Answer 44

In ribosomes.

Question 45

What is Chargaff’s Rule?

Answer 45

A = T and G = C in DNA.

Question 46

What is a nucleosome?

Answer 46

DNA wrapped around histones.

Question 47

What is DNA base stacking?

Answer 47

Interactions between adjacent bases that stabilize DNA.

Question 48

What did Friedrich Miescher call DNA?

Answer 48

Nuclein.

Question 49

What type of bonds hold DNA base pairs together?

Answer 49

Hydrogen bonds.

Question 50

What feature of DNA ensures genetic stability during replication?

Answer 50

Complementary base pairing.