Unit 2

Question 1

DNA stands for

Answer 1

Deoxyribonucleic acid

Question 2

DNA is:

Answer 2

The biological molecule of inheritance

Question 3

How long is DNA code?

Answer 3

Six billion letters long

Question 4

What are the four bases in DNA, and what are their pairings?

Answer 4

Adenine + Thymine

Guanine + Cytosine

Question 5

What are nucleotides?

Answer 5

The building blocks of DNA

Question 6

A polymer is made of what?

Answer 6

Monomers

Question 7

What are the sides of DNA made of?

Answer 7

Sugar (deoxyribose) and phosphate

Question 8

Adenine and guanine are what?

Answer 8

Purines (2 Carbon rings)

Question 9

Thymine and cytosine are what?

Answer 9

Pyrmidines (1 carbon ring)

Question 10

Nucleotides are connected to one another by what?

Answer 10

Covalent bonds between the phosphate and sugar

Question 11

When bases are paired, what holds them together?

Answer 11

Hydrogen bonds

Question 12

DNA replication (the copying of DNA) occurs before what?

Answer 12

Mitosis or meiosis

Question 13

DNA replication occurs where?

Answer 13

In the nucleus, during interphase (right before prophase)

Question 14

What happens when DNA is replicated?

Answer 14

One half of the DNA strand is a parent strand, the other half a daughter strand (semi-conservative)

Question 15

What does helicase do?

Answer 15

UNWINDS the DNA strand by breaking the hydrogen bonds between bases

Question 16

What does DNA polymerase do?

Answer 16

BUILDS new DNA strand by “reading” the parent strand and “matching” nucleotides

Question 17

What does primase do?

Answer 17

Initializes the entire process and SETS A PATH for the polymerase to follow.

Question 18

What does ligase do?

Answer 18

GLUES Okazaki fragments on the lagging strand

Question 19

What’s the first step of DNA replication?

Answer 19

1. Origin is discovered and the strand is wound and unzipped, forming a replication fork

Note: there maybe be more than one site of origin

Question 20

What’s the second step of DNA replication?

Answer 20

2. Single stranded bonding proteins bind to each of the DNA sides to keep the zipper unwound

Question 21

What;s the third step of DNA replication?

Answer 21

3. Primase forms a primer or both sides of the unzipped parent DNA

Question 22

What’s the fourth step of DNA replication?

Answer 22

4. DNA polymerase recognizes the primer and uses free nucleotides to build the new DNA strand by using the parent code

Question 23

What’s the fifth step of DNA replication?

Answer 23

5. Covalent bonds are formed between phosphates and sugars

Note: DNA is antiparallel—therefore each strand is built differently; one is leading and the other is lagging, therefore built in small fragments

Question 24

What’s the sixth step in DNA replication?

Answer 24

6. DNA polymerase reads the DNA 3’-5’ (building 5’-3’)

Question 25

What’s the seventh step in DNA replication?

Answer 25

7. Ligase joins the Okazaki fragments on the lagging side

Question 26

What is required for sustaining life?

Answer 26

Proteins

Question 27

What are proteins used for after they’re broken down in digestion?

Answer 27

Proteins are rebuilt for traits

Question 28

What does RNA stand for?

Answer 28

Ribonucleic acid

Question 29

What’s RNA?

Answer 29

A biomolecule made of nucleotides?

Question 30

What’re some differences between DNA and RNA?

Answer 30

DNA: - codes for traits - deoxyribonucleic acid - double helix - found in nucleus - sugar: deoxyribose RNA: - used in protein synthesis - ribonucleic acid - single stranded - nucleus + cytoplasm - sugar: ribose

Question 31

What’s the difference between DNA bases and RNA bases?

Answer 31

RNA doesn’t have thymine: it has uracil

Question 32

How many types of RNA exist compared to DNA?

Answer 32

There are three types of RNA, one type of DNA

Question 33

What’s transcription? (Step 1)

Answer 33

- DNA is transcribed into a small message (mRNA) to be carried to a ribosome - RNA polymerase (enzyme) is used to “read” by “matching” DNA code with RNA bases - mRNA is transported out of nucleus - single stranded mRNA leaves and finds a ribosome in the cytoplasm

Question 34

What’s translation? (Step 2–cytoplasm)

Answer 34

- mRNA moves to a ribosome made of rRNA (ribsomal RNA) where the protein is assembled - tRNA (transfer RNA) carries amino acids according to its anti-codon (associated w/ tRNA) - mRNA holds the codons