Microbiology exam 3

What are the major functions of proteins in a cell?

1. Enzymes

2. Structural support

3. Transport

4. Regulators

5. Defense

6. Movement

7. communication

What Speeds up chemical reactions in a cell

Enzymes

What gives the cell its shape and support

Structural proteins

What moves substances across membranes in a cell

Transport proteins

What turns genes on or off

Regulator proteins

What protects the cells

Defense proteins

What helps the cell move

Movement proteins

What type of protein helps with communication

Signaling proteins

What is the molecule that stores genetic information, contains the instructions for making proteins, instructions for regulating cell activity, and passes hereditary information?

DNA

What is the basic building block of DNA

Nucleotide

What is part of the backbone of DNA

And helps link one nucleotide to the next

Phosphate group

What is a 5- carbon sugar, and specific to DNA

Deoxyribose

What is a 5 carbon sugar specific to RNA

Ribose

What part of the Nucleotide changes from one nucleotide to another

Nitrogen base

What are the 4 parts of a nitrogen base

Adenine,Thymine, Cytosine, Guanine

What are the 3 parts of a nucleotide

Phosphate group, Deoxyribose, Nitrogen base

What base is found only in DNA and pairs with Adenine

Thymine

What base is a nitrogen containing base that pairs only with thymine

Adenine

What base pairs only with guanine

Cytosine

what base only pairs with cytosine

Guanine

What bases are called purines

A and G

What bases are called Pyrimidines

C and T

True or False

A purine always pairs with a pyrimidines

True

What is the specific, consistent connection between nitrogenous bases on opposite strands of DNA or RNA

Complementary base pairing

True or False

The Pairs of DNA bases are held together by hydrogen bonds

True

How many hydrogen bonds are formed when A and T pair up

2

How many hydrogen bonds are formed when C and G pair up

3

True or False

DNA regions with C and G pairs can be harder to separate explain why

True, because Cytosine and Guanine pairs make more hydrogen bonds

Sides of the DNA are made of these 2 things alternating

Sugars and phosphates

What does it mean when we say DNA strands are Antiparallel

If one DNA strands run 5 to 3 the other runs 3 to 5

True or False

5 end usually has a phosphate attached to the 5 carbon

True

True or False

3 end usually has hydroxyl group on the 3 carbon

True

Why is the Antiparallel structure important

It allows proper base pairing

It allows enzymes to function correctly

It explains leading and lagging strands

What is DNA structured like

Double Helix, 2 strands twisted around each other

List all the things DNA has

2 strands

Complementary base pairing

Antiparallel strands

Sugar-Phosphate backbone

Double helix

DNA synthesis (building a new strand) always occurs in which direction?

5 and 3

What is the main function of complementary base pairing in DNA?

To allow accurate DNA replication

Which component of DNA is responsible for carrying genetic information?

Nitrogenous bases

What is the main goal of DNA replication?

To make an exact copy of DNA before cell division

What does semiconserative mean

Each DNA is one old strand plus 1 new strand

what is the specific location on DNA where replication begins called

The origin of replication

What are the 4 steps of replication

Initiation

Unwinding

Elongation

Termination

This step of replication begins at origin of replication

DNA double helix starts opening

Helicase Breaks down hydrogen bonds

Topoisomerase/gyrase relives twisting tension

Initiation

In this step of replication strands separate more fully

Primase lays down RNA primers

Gives DNA polymerase a starting point

Unwinding or Priming

In this step of replication DNA polymerase III adds new nucleotides

Where new DNA is made of 5-3

where Leading strand is continuous and Lagging strand is discontinuous

Elongation

In this step of replication

DNA polymerase I removes RNA primers and replaces with DNA

Lipase seals the gaps

Termination

Which type of strands are built in pieces and are in opposite directions

Lagging strands

Which types of strands are built continuously

Leading strands

What is a Short DNA fragment on lagging strands and are later joined together

Okazaki Fragments

What type of fragment seals gaps between the Okazaki fragments and forms phosphate bonds

Joining fragments

This enzyme removes RNA primers and replaces them with DNA

DNA polymerase I

This enzyme is the main enzyme for building DNA, and adds nucleotides

DNA polymerase III

This enzyme breaks down hydrogen bonds in the initiation stage of replication, It also Unzips the DNA helix

Helicase

This enzyme Relieves tension or supercoiling and is also part of the initiation stage of replication

Topoisomerase

This enzyme adds RNA primer its part of the second stage of replication

Primase

This Enzyme joins Okazaki fragments and seals “nicks” in DNA backbone it is also part of the termination stage in replication

DNA Ligase

What is a segment of DNA that codes for protein

Gene

The process by which genetic information is turned into a product

Gene expression

DNA stores info

RNA carries info

Protein preforms function

Central Dogma of Molecular biology

What are the 2 main steps of Gene expression

Transcription and translation

In which step of gene expression is DNA turned into RNA

Transcription

In which step of gene expression is RNA turned into protein

Translation

Where does transcription occur

Cytoplasm (prokaryotes)

What type of RNA carries genetic code to ribose

mRNA

Which type of RNA brings amino acids

tRNA

Which type of RNA makes ribosome

rRNA

What is the process where RNA is turned into protein

Translation

Where does translation occur

Ribosome

What are the 3 steps for transcription

Initiation, elongation, termination

In this stage of transcription, Ribose attaches to mRNA and starts codon AUG

Initiation

In this stage of transcription

tRNA brings in amino acids and ribosome links them with peptide

RNA polymerase builds RNA strand

Elongation

What pairs with Adenine in transcription

Uracil

In this stage of transcription: RNA polymerase reaches stop sequence RNA strand released

Termination

What enzyme builds RNA strand, works in 5 to 3

RNA polymerase

What are the steps of translation

Initiation, Elongation, Termination

In what stage of transcription does Ribosome attaches to mRNA, and starts codon AUG

Initiation

In what stage of transcription does tRNA brings amino acids Ribosome links them with peptide bonds

Elongation

Codon has

3 bases on mRNA

Anticodon has

3 bases on tRNA

In this stage of transcription stop codon is reached, and protein is released

Termination

what is a 3-base sequence on mRNA and Codes for amino acid

Codon

What is a Complementary sequence on tRNA

Anticodon

What is the bond between amino acids

Peptide bond

What is the DNA strand used to build RNA called

Template strand

What is a group of genes controlled together

Operon

What are the 3 parts of an operon

Promoter, Operator, Genes

which part of an operon does RNA polymerase bind

Promoter

which part of the operon is the on/off switch

Operator

What part of the operon codes for proteins

Genes

What is a protein that blocks transcription called

Repressor

What sits on the operator, and stops RNA polymerase

Repressor

What is a molecule that turns genes ON

Inducer

What binds to the repressor, changes its shape making it fall off

Inducer

What type of system is only off, and on only when lactose is present

INDUCIBLE SYSTEM or LAC

What type of system is only on and turned off

. REPRESSIBLE SYSTEM or TRP

What does it mean when bacteria share DNA with one another

Horizontal gene transfer

Why can bacteria become antibiotic resistant FAST,

gain new traits quickly, evolve rapidly

Horizontal gene transfer

what is it called when Bacteria pick up free DNA from environment, DNA comes from dead bacteria

Transformation

True or false

Transformation is when bacteria takes DNA from surroundings

True

what is it called when One bacterium transfers DNA to another Uses a sex pilus

Conjugation