Unit 3 LC #1

Question 1

What are Genes?

Answer 1

A distinct pattern or sequence of nucleotide bases within a chromosome

Question 2

What are the purpose(s) of Genes?

Answer 2

The specialized pattern of Genes determine the traits of the organism they reside in

Question 3

What are Nucleotides?

Answer 3

The monomers of Nucleic Acid who’s bases make up Amino Acid sequences

Question 4

What are Nucleotides made up of?

Answer 4

• 1 Sugar Molecule
• 1 Phosphate Group
• 1 Nitrogenous Base

Question 5

What are the 4 Nucelotide bases of DNA and what do they pair with?

Answer 5

• Adenine (A), bonds with T
• Cystosine (C), bonds with G
• Guanine (G), bonds with C
• Thymine (T), bonds with A

Question 6

What are the 4 Nucelotide Bases of mRNA and what do they pair with?

Answer 6

• Adenine (A), bonds with U
• Uracil (U), bonds with A
• Guanine (G), bonds with C
• Cytosine (C), bonds with G

Question 7

What is mRNA, and how is it physically different from DNA?

Answer 7

Messenger RNA, or mRNA, is a single-stranded helix structured nucleic acid.

Question 8

What is the function of mRNA?

Answer 8

It carries messages from the DNA to active sites of the body in order to tell it how to make proteins, since original DNA molecules must stay within nuclei. (This is called protein synthesis)

Question 9

What is Protein Synthesis?

Answer 9

The processes in which cells (being instructed by DNA/RNA make protein for the body.

Question 10

What are the steps of Protein Synthesis and where do they occur?

Answer 10

1. Transcription - A strand of DNA being copied into mRNA for the message to be carried (it occurs in the Nucleus in Eukaryotes, and the Cytoplasm in Prokaryotes)
2. Translation - mRNA using the DNA’s genetic information to instruct cells how to link Amino Acids and create Protein (It occurs in the Cytoplasm and Rough E.R)

Question 11

In Translation, how are Nitrogenous Bases read?

Answer 11

Being packaged in Codons, Nitrogenous Bases are read in triplets, 3 at a time before the next and in 3 stations

Question 12

What happens after all Nitrogenous Bases are read and turned into Amino Acids?

Answer 12

The Amino Acids formed from Translation eventually fold into shape atop one another to make a globular ball looking shape known as a Protein

Question 13

How does the reading begin in Translation?

Answer 13

The site of production must first read the codon instructing it to start reading, which is AUG, or “Met”

Question 14

How does the reading stop in Translation?

Answer 14

The site of protein production stops reading once it scans one of three codons instruction it to stop reading, which are UAA, UAG, and UGA, all decoding to “Stop”

Question 15

What is the overall relationship between DNA, Proteins, and Functions of Life?

Answer 15

DNA is responsible for providing genetic code in order to create Proteins, which in turn give the bearer of these Proteins traits, which determine their life functions

Question 16

What is a Chromosome?

Answer 16

A threadlike structure composed of 2 DNA molecules (which is why it looks like an “X”), being found in the Nucleus of each cell.

Question 17

How many Genes are present in a Chromosome?

Answer 17

Hundreds to thousands of Genes can be within a Chromosome

Question 18

Where do Chromosomes come from, and how many are there?

Answer 18

Half of your Chromosomes come your birth mother (23), and half from your father (23), making 46 total chromosomes in a human

Question 19

What is DNA Replication?

Answer 19

The process in which DNA makes an identical copy of itself through/during cell division

Question 20

What are the steps of DNA Replication, and what happens in them?

Answer 20

1. Initiation - DNA unzips into two, exposing half of it’s bases and getting ready for pairing
2. Elongation - Nucleotides searching for matching bases to align and bond with
3. Termination - The completion of DNA Replication after Okazaki Fragments are binded, resulting in two remaining DNA molecules ready for work

Question 21

What are the 4 Enzymes involved in DNA replication, and what do they do?

Answer 21

• DNA Helicase - “Unzipping Enzyme”, it unzips the DNA
• DNA Polymerase - “The Builder” Builds new DNA strand after Helicase unzips
• DNA Primase - “The Initializer”, Indicates and marks where DNA Polymerase needs to go for building
• DNA Ligase - “The Gluer” - Glues DNA fragments together after being built, in order to have a fully-functioning double helix DNA strand

Question 22

Which steps of DNA Replication involve which Enzymes?

Answer 22

1. Initiation - (Helicase) unzips through DNA strand at point of origin, then different parts are marked by (Primase)
2. Elongation - After seeing marked points done by (Primase), (DNA Polymerase) comes in and builds up a new strand step-by-step at marked locations
3. Termination - (Ligase) comes in and glues Okazaki Fragments together at Primer locations, which eventually form an entirely new DNA molecules

Question 23

What are Okazaki Fragments?

Answer 23

Short sequences of DNA nucleotide strands which need to be linked and glued by DNA Ligase in order for the completion of a new DNA Molecule (They are also known as Lagging Strands)

Question 24

What are Leading and Lagging strands in DNA replication?

Question 25

What is the prime difference between the Leading and Lagging strands in DNA replication?

Answer 25

Aside from their differing synthesizing points, the Leading strand is synthesized continuously until completion, while the Lagging strand is synthesized in portions due to it’s multiple Okazaki Fragments

Question 26

How many types of RNA are there? What are they called and what do they do?

Answer 26

There are 3 primary types of RNA

• Messenger RNA (mRNA) - It carries and provides instructions from DNA in order to conduct Protein Synthesis
• Transport RNA (tRNA) - It carries Amino Acids for distribution once it reads the genetic code during Translation
• Ribosomal RNA (rRNA) - It provides structure/shelter, and acts as a catalyst during Translation

Question 27

What are Genetic Mutations?

Answer 27

Mutations result from changes in/to DNA sequence, causing abnormalities in Amino Acid production

Question 28

When/how do Mutations occur?

Answer 28

During Cell Division and/or Protein Synthesis, if part of an mRNA codon is read incorrectly, the Amino Acid is changed, resulting in something other than intended

Question 29

How many kinds of Mutations are there? What are they called?

Answer 29

There are 4 different Mutation types

• FRAMESHIFT - Reading frame has been fed the wrong codon, changing the AA sequence from that point forward
• MISSENSE - mRNA read wrong, causing a singular AA change
• SILENT - mRNA read wrong, but no change(s) to AA
• NONSENSE - mRNA read wrong, producing an AA that forces reading to STOP

Question 30

How many causes of Mutations are there? What are they? What mutations do they cause?

Answer 30

There are 3 different causes of Mutations.

• DELETION - A base is lost/deleted (This results in a FRAMESHIFT Mutation)
• Insertion - An additional base is added/inserted (This results in a FRAMESHIFT Mutation)
• Substitution - One base is swapped/substituted for another (This may result in a MISSENSE, SILENT, or NONSENSE Mutation)

(REMEMBER: Deletion and Insertion will ALWAYS result in FRAMESHIFT Mutations!)

Question 31

What is Sickle Cell Anemia the result of?

Answer 31

It results from a type of Mutation in the genes that codes for only part of the Hemoglobin molecule.

Question 32

What order are DNA Replication Enzymes used in?

Answer 32

1. DNA Helicase (Unzips)
2. DNA Primase (Marks build points)
3. DNA Polymerase (Builds at Primer points)
4. DNA Ligase (Glues the fragments together to complete the DNA strand)