Lecture 1

Question 1

What separates eukaryotic cell from prokaryotic cells?

Answer 1

Eukaryotic cells have a nucleus and membrane enclosed organelles. Prokaryotic doesn’t have those.

Question 2

What all cells have in common?

Answer 2

They have genetic material, cytoplasm and cell membrane

Question 3

What is special about viruses, vioids and prions?

Answer 3

They cannot reproduce on it’s own. They must infect host-cell to reproduce.

Question 4

What are viruses and virions and what they consists of?

Answer 4

Small infectious particles without cell structure.

Nucleic acid molecules either DNA or RNA

Question 5

What are prions and what they infect?

Answer 5

Infectious protein particles without nucleic acid.

Infect cells in the nervous system

Question 6

Storage of information in prokaryotic cells?

Answer 6

Nucleoid: DNA and RNA molecules with nucleoproteins, membrane free.

DNA: circular, not attached with histones

Plasmids

Question 7

Genetic information in prokaryotic cells? Copies?

Answer 7

Only one copy, haploid organism

Question 8

Nuclear DNA in eukaryotic cell? genomes?

Answer 8

Linear or double-stranded.

Diploid genome in somatic cells, haploid genome in germ cells

Question 9

Mitochondrial DNA in eukaryotic cell? genomes?

Answer 9

Circular and double-stranded.

Copies of mtDNA varies and depends on cell function

Question 10

Something about somatic cells?

Answer 10

Takes part in formation of the body.
Not involved in reproduction.
Contains two copies of genetic information (diploid)

Question 11

Something about germ cells?

Answer 11

Sexual reproductive cell at any stage.

Contains one copy of genetic information (haploid)

Question 12

What are nucleic acids made of?

Answer 12

Made up of monomers called nucleotides

Question 13

Three components of nucleic acid?

Answer 13

• 5 carbon sugar
• phosphate functional group
• nitrogenous base

Question 14

DNA vs RNA 5 carbon sugar?

Answer 14

Deoxyribose vs ribose

Question 15

DNA vs RNA nitrogenous base?

Answer 15

Thymine vs uracil

Question 16

What is ATP, modified nucleotide?

Answer 16

Energy processor in cells.
Serves as a temporary energy battery.
When energy is needed the last phosphate group is removed

Question 17

How is sugar-phosphate backbone formed?

Answer 17

By dehydration synthesis

or polymerization reactions, between the sugar of one nucleotide and the phosphate group of one nucleotide

Question 18

How are the two strands of nucleic acid hold together?

Answer 18

By forming a hydrogen bonds, G with C and A with T or U

Question 19

How does the double-helix shape formed?

Answer 19

They are antiparallel, one strand goes to 5-3 direction, and other to 3-5

Question 20

Important biological functions of nucleic acids? Many! Start with DNA

Answer 20

DNA: storage of information

RNA: realization of information

mRNA

tRNA

rRNA:

Regulatory RNA

Question 21

Regulatory RNA?

Answer 21

Noncoding RNA molecules, does not transfer to proteins. Role in epigenetic regulation

Question 22

tRNA?

Answer 22

transfer RNA, binds activated amino acid and deliver it to the ribosomes for protein synthesis

Question 23

rRNA?

Answer 23

ribosomal RNA, catalyse formation of peptide bounds and controls precise binding of mRNA

Question 24

mRNA?

Answer 24

messenger RNA, synthesized during transcription, delivers copied information to cytoplasm

Question 25

In DNA replication, how does the process start?

Answer 25

By separating the two strands. An enzyme called helicase does this. This is how the replication fork is made.

Question 26

How does the DNA replication continues after the separation of two strands?

Answer 26

An enzyme called primase starts the process by making RNA bases which is called a primer

Question 27

After the initiation of primer, what happens in DNA replication?

Answer 27

An enzyme called DNA polymerase binds to the primer and makes the new strand of DNA by making DNA bases in 5-3 direction

Question 28

The strand which can be made continuously is called?

Answer 28

The leading strand

Question 29

How is the lagging strand build by?

Answer 29

DNA polymerase adds small chunks of DNA bases one by one = okizaki fragments

Question 30

What happens after the new strand of DNA is made in DNA replication?

Answer 30

The enzyme exonuclease removes the RNA primers, then another DNA polymerase fills the gaps with DNA

Question 31

What does the enzyme ligase do?

Answer 31

Seals up the fragments of DNA in both strands by forming a continuous double strands

Question 32

What is special about viroids?

Answer 32

Only RNA, infect plants.