Molecular Genetics

Front 1

What is DNA?

Back 1

deoxyribonucleic acid--composed of a 5-carbon sugar called deoxyribose. Polymer of nucleotides.

Front 2

What are the four nucleotides?

Back 2

guanine, cytosine, adenine, thyamine

Front 3

DNA is considered redundant which means?

Back 3

has two halves--if you know one half, you know the other half

Front 4

What does semi-conservative mean as it applies to DNA synthesis?

Back 4

Half of the DNA is used as a template to make the rest of the DNA because it is redundant

Front 5

What is meant by DNA being semi-conservative?

Back 5

During DNA synthesis, half of DNA is used to make a template for making the rest of the DNA

Front 6

What does DNA polymerase do?

Back 6

binds the new DNA to the unzipped DNA

Front 7

What does DNA helicase do?

Back 7

unzips the DNA for DNA synthesis

Front 8

DNA polymerase chain-reaction

Back 8

DNA helicase unzips DNA, DNA polymerase creates and binds new copy of DNA to unzipped DNA. Done over and over again.

Front 9

What are the three steps of DNA synthesis?

Back 9

1.)unwinding 2.)complimentary pairing 3.)joining

Front 10

Which step(s) of the DNA synthesis process uses DNA polymerase?

Back 10

complimentary pairing and joining

Front 11

Which step(s) of the DNA synthesis process uses DNA helicase?

Back 11

unwinding

Front 12

What is the outcome of DNA synthesis?

Back 12

two exact copies of DNA

Front 13

Where does DNA synthesis occur in prokaryotic cells?

Back 13

One strand of DNA in a loop--occurs at the loop's connection point and can replicate to the left, right or both directions

Front 14

Where does DNA synthesis occur in eukaryotic cells?

Back 14

Unwinding can occur at one end and go to the other end, but typically it occurs in many different points along the DNA strand

Front 15

What is a replication bubble?

Back 15

Unwinding of the DNA that occurs in both directions along the DNA strand

Front 16

Can there be multiple replication bubbles?

Back 16

Yes multiple replication bubbles make the replication process much faster.

Front 17

What do genes code for?

Back 17

genes code for proteins--some are structural and some are enzymes

Front 18

What is a codon?

Back 18

A combination of three nucleotides which code for an amino acid

Front 19

How many different combinations of codons are there? How many amino accids?

Back 19

There are 64 combinations of codons. Only 20 amino acids. This means some codons code for the same amino acids.

Front 20

What are the two parts of protein synthesis?

Back 20

Transcription and translation

Front 21

What is transcription and where does it occur?

Back 21

Transcription is the making of a copy of the DNA and occurs in the nucleus

Front 22

What is translation and where does it occur?

Back 22

translation occurs in the cytoplasm in the ER via ribosomes. Nucleic acids are translated into amino acids.

Front 23

Can DNA leave the nucleus? Can RNA? Why?

Back 23

DNA cannot leave but RNA can because it is smaller and can leave by diffision. DNA is too large.

Front 24

What is RNA?

Back 24

Ribonucleic acid--single-stranded polymer of nucleotides found in either the nucleus or the cytoplasm.

Front 25

What replaces thyamine in RNA?

Back 25

uracil

Front 26

Are the RNA and DNA templates the same?

Back 26

No. Same amino acids, same information, but slightly different because they are different sugars.

Front 27

What does RNA polymerase make?

Back 27

mRNA which is messenger RNA

Front 28

What are the three kinds of RNA?

Back 28

mRNA, tRNA (transfer RNA), and rRNA (ribosomal RNA)

Front 29

True or false? Ribosomes are not membrane-bound organelles.

Back 29

TRUE. Ribosomes are rRNA!!!

Front 30

What is a promoter?

Back 30

the promoter is a DNA sequence that allows a gene to be transcribed.

Front 31

Where does RNA polymerase attach to?

Back 31

The promoter which in turn activates the operator to create a particular chemical reaction

Front 32

What is the operator?

Back 32

The operator is a segment of DNA where the regulator protein binds.

Front 33

What does a repressor do? Where does it attach?

Back 33

prevents RNA polymerase from attaching to promoter. Repressor attaches to operator.

Front 34

What does an activator do?

Back 34

protein made by a regulator gene which turns an operon on or off

Front 35

Operons are used in what kinds of cells, prokaryotic or eukaryotic?

Back 35

Prokaryotic cells

Front 36

What are the four controls used in eukaryotic cells in gene regulation?

Back 36

transciptional control, post-transcriptional control, translational control, and post-translational control

Front 37

What is translational control?

Back 37

more product? increase transcription

Front 38

What is post-translational control?

Back 38

increase splicing to make mature RNA (necessary to be used)

Front 39

What is translational control?

Back 39

mature RNA transcribed with ribosomes to make protein=more product--control how many ribosomes attache to RNA

Front 40

What is post-translational control?

Back 40

Regulates pH needed to activate the protein--control environment to control shape, regulates activity of the gene

Front 41

What is a mutation?

Back 41

altering of the DNA--typically permanent and influences the sequence of nucleotides

Front 42

What is point-mutation?

Back 42

one nucleotide in the sequence changes altering the amino acid represented. Example--GCA to GCT

Front 43

Where does eukaryotic gene regulation occur?

Back 43

In the nucleus

Front 44

What is an example of point-mutation?

Back 44

sickle-cell anemia--one nucleotide changes the shape of the red blood cells making them unable to carry oxygen as well

Front 45

What is a frame-shift mutation?

Back 45

occurs during insertion or deletion and can cause serious damage

Front 46

What is a cancerous gene called?

Back 46

Oncogenic

Front 47

What gene is typically associated with cancerous tumors?

Back 47

P-53 which is a tumor suppressor gene--when it is not functioning, tumors develop--#1 cause of cancer in humans!