Gen Bio 1 unit 4 exam (simplified)

translator

the process that takes the information passed down from DNA as a messenger RNA and turns it into a series of amino acids bound together by peptide bonds. It is essentially a translation from one code (nucleotide sequence) to another code (amino acid sequence)

transcription

The process of making an RNA copy of a gene’s DNA sequence. This copy then carries the gene’s protein information encoded in DNA. 

translation

The process that takes the information passed from DNA as a messenger RNA and turns it into a series of amino acids bound together with peptide bonds. 

DNA structure

DNA is double stranded, forming a double helix. DNA is deoxyribose. DNA uses the bases adenine, thymine, cytosine, and guanine. RNA uses adenine, uracil, cytosine, and guanine

RNA structure

RNA is usually single stranded, RNA contains ribose. RNA uses adenine, uracil, cytosine, and guanine

DNA replication

_____ creates identical DNA strands

transcription

_____ converts DNA into messenger RNA (mRNA). Translation then decodes mRNA into amino acids, forming proteins needed for life functions.

RNA polymerase

Transcribes the genetic information stored in DNA to RNA. The _______ produces a single stranded RNA molecule. Both polymerases require a DNA template strand and free nucleotides

DNA polymerase

_____ produces a double stranded DNA molecule, Both polymerases require a DNA template strand and free nucleotides

TATA box

The ____ can define the direction of transcription and indicates the DNA strand to be read. Proteins called transcription factors bind to the _____ and recruit an enzyme called RNA polymerase, which synthesizes RNA from DNA. 

RNA processing

The sequence of events through which the primary transcript from a gene acquires its mature form. Both prokaryotes and eukaryotes process their ribosomal and transfer RNAs. The major difference, however, is in the processing messenger RNAs

What is the difference between a primary transcript and a “finished” mRNA. Are they the same in eukaryotes? Are they the same in prokaryotes? Why?

3 types of RNA’s

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

codons

A _____ is a three-letter genetic sequence found in both DNA and RNA. It codes for a specific amino acid or start and stop signals for the protein synthesis process

anti-codon 

A unit of 3 nucleotides that are complementary to a mRNA codon. It identifies which tRNA binds to which mRNA. They are located at one end of a transfer RNA molecule

template strand

The DNA sequence that can duplicate itself during mRNA synthesis

codon chart

How can you decipher the genetic code? 

yes

(ex: human insulin gene was used to transform bacteria)

Can you take a gene from a human and put it in a bacterium?

5’-3’ designation

The two strands of DNA double helix are antiparallel, this 5’-3’ DNA synthesis can take place continuously on only one

promoters? 

A region of DNA where transcription of a gene is initiated. Helps RNA polymerase to find where a gene starts 

5’ caps

The group at the beginning (5’ end) is called a ____, Both the _____ and tail protect the transcript and help it get exported from the nucleus and translated onto the ribosomes found in the cytosol. They are found in eukaryotic cells. 

poly-A tails

The group at the end (3’ end) is called a ____.Both the 5’ cap and ____ protect the transcript and help it get exported from the nucleus and translated onto the ribosomes found in the cytosol. They are found in eukaryotic cells. 

introns

An _____ refers to the non-coding sequences found in DNA or RNA.

exons

____ refers to the coding portions of DNA or RNA. 

heteronuclear RNA

Transcribed RNA that has not been processed.

protein domains

The exons match the _____, then duplication, permutation and rearrangement of such exons would create 

The ribosome 

Where does a tRNA line up to a mRNA?

stages of protein synthesis.

Initiation, elongation, and termination

AUG 

What is the start codon?

Methionine

What amino acid is the first in every protein made?

The endoplasmic reticulum 

Where are secreted proteins synthesized? Why? 

The ribosomes 

Where are proteins that work in the cytoplasm synthesized? 

UGA

A stop signal in the universal genetic code, or the terminator codon. 

AUG 

The standard start codon for translation of a gene, encodes the amino acid methionine (Met or M). It also establishes the reading frame for the ribosome to follow, adding corresponding amino acids in a polypeptide chain. 

amino-acyl-tRNA synthetase 

An enzyme that attaches the appropriate amino acid onto its corresponding tRNA 

tRNA molecule

Contains a set of three nucleotides called an anticodon. The anticodon of a given___can bind to one or more specific mRNA codons. Its “L shaped structure” functions as an adaptor that translates this codon sequence in the mRNA into the suitable amino acid of that codon. As the link between amino acids and nucleic acids,____ determine the genetic code. 

small ribosomes

decode the genetic information

large ribosomes

catalyze peptide bond formation. 

initiation 

In _____, the ribosome gets together with the mRNA and the first tRNA so translation can begin. 

elongation

prokaryotes

In _____, protein synthesis is coupled, meaning transcription and translation occur simultaneously.

eukaryote

in _____ protein synthesisit occurs in stages.

central dogma

theory stating that genetic information flows only in one direction, from DNA, to RNA, to protein, or RNA directly to protein. 

polyribosomes

Increases the efficiency of protein production by a single mRNA. They are found in eukaryotes. 

types of point mutations 

missense, nonsense, silent

missense point mutation

a DNA change that results in different amino acids being encoded in different amino acids being encoded at a particular position in the resulting protein. 

nonsense point mutation

a change in DNA that causes a protein to terminate or die or end its translation earlier than expected. 

silent point mutation

mutations in DNA that do not have an observable effect on the organism's phenotype 

frameshift mutation

A genetic mutation caused by a deletion or insertion in a DNA sequence that shifts the way the sequence is read.  

vertical exchange of genetic material

refers to the passage of plasmid from mother to daughter cells.

horizontal exchange of genetic material

refers to the passage of a plasmid from donor to any recipient outside of cell division (often through conjunction).

transformation

The process by which foreign genetic material is taken up by a cell. 

transduction

The process by which a virus transfers genetic material from one bacterium to another.  

conjugation

The process by which one bacterium transfers genetic material to another through direct (“donor”) contact. 

pilus

A ___ is a thin, rigid fiber made of protein that protrudes from the cell surface. The primary function of ____ is to attach to a bacterial cell to specific surfaces to other cells.

plasmid

A small circular DNA molecule found in bacteria and some other microscopic organisms. 

antibiotics

Medicines that fight bacterial infections in people and animals. They work by killing the bacteria by making it hard for the bacteria or by making 

yes ?

Do eukaryotic cells typically have plasmids that are used to transmit genetic information? 

operon

A functioning unit of DNA containing a cluster of genes under the control of a single promoter. 

operator

The DNA sequence where the repressor molecule binds to the operon model. Present in both eukaryotes and prokaryotes.

promoter

A region of DNA where transcription of e gene is initiated. 

repressor

A protein that inhibits the expression of one or more genes. Works by binding to the promoter region of the gene(s), which prevents the production of messenger RNA (mRNA).

tryptophan

An amino acid needed for normal growth in infants and for the production and maintenance of the body’s proteins, muscles, enzymes, and neurotransmitters. It is an essential in amino acids 

Amino acids (in polypeptide chains)

What macromolecules are enzymes made of?

corepressor

Proteins that regulate the process of gene expression indirectly by binding to the repressor protein. Operates with the transcription factors to reduce the rate of gene transcription. 

lactose

The principal sugar (or carbohydrate) is naturally found in milk and dairy. Composed of glucose and galactose.  

repressor proteins

_____ bind to DNA and prevent RNA polymerase from being able to attach to the DNA and synthesize mRNA.

inducer proteins

_____ bind to repressors, causing them to change shape and preventing them from binding to DNA. 

Anabolic

What type of pathways (anabolic or catabolic) are usually controlled by repressible enzymes?

Increased cAMP leads to enhanced expression

How does cAMP contribute to the control of the lac operon? 

lac operon

A set of structural genes that code for proteins to digest lactose, that can be turned on and off.  

bacterial and eukaryotic gene control

Both rely on proteins that act as activators that “turn on” gene expression or repressors that “turn off” gene expression. 

cell differentiation

How generic embryonic cells become specialized cells. This occurs through a process called gene expression. 

The process by which dividing cells change their functional or phenotypical  

histones

A protein that provides structural support for a chromosome. 

chromosome

histones assist in DNA packaging:

DNA wraps around the histone proteins which helps give the _____ a more compact shape. 

nucleosome

Serves as a gene repressor, and a repressor of all transcription factors.

Tandem repeats, Interspersed repeats, Terminal repeats

3 types of repetitive DNA

Tandem repeats

serves as genetic markers to track inheritance in families. 

Interspersed repeats

Terminal repeats

Huntington’s Disease and fragile X syndrome 

What conditions result from triple repeats of DNA sequences? 

gene families 

Groups of homologous genes that are likely to have highly similar functions.  

myoglobin

Myoglobin has only one polypeptide chain, and its function is to store the oxygen for use by muscle tissue.  

hemoglobin

______ has 4 polypeptide chains, and its function is to transport oxygen.

the initiation f transcription 

Explain at which steps/level of the central dogma gene expression can be controlled in eukaryotes. 

epigenetics 

The study of how your behaviors and enviroment can cause changes that affect the way your genes work

DNA methylation

Regulates gene expression by recruiting proteins involved in gene repression or by inhibiting the binding of transcription factors to DNA. 

acetylation

A critical epigenetic modification that changes chromatin architecture and regulates gene expression by opening or closing the chromatin structure. 

 Nucleic acids and proteins 

what macromolecules are viruses made of?

obligate parasite

A parasitic organism that is not able to complete its life cycle without exploitation of suitable host. 

retrovirus

A virus that uses RNA as its genomic material. 

direct contact with contaminates.

How do flu virusus go from infecting animals to humans? Acquired through direct contact with infected animals or contaminated environments.

Double-stranded DNA, double-stranded RNA, single-stranded DNA, or single-stranded RNA. 

Describe 4 different type of nucleic acids that viruses may contain.

‘enveloped’ virus 

The outermost layer of many types of viruses. It protects the genetic material in their life cycle when traveling within host cells. Not all viruses have envelopes.

bacteriophage

Viruses that infect and replicate only in bacterial cells. 

lytic cycle

• The _____is a phage replicative cycle that culminates in the death of the host cell​

• The ____ produces new phages and lyses (breaks open) the host’s cell wall, releasing the progeny viruses​

• A phage that reproduces only by the ______ is called a virulent phage

Involves the reproduction of viruses using a host cell to manufacture more viruses; the viruses then burst out of the cell. ​

lysogenic cycle

• The ______ replicates the phage genome without destroying the host​

• The viral D N A molecule is incorporated into the host cell’s chromosome​

• Phages that use both the lytic and ______ cycles are called temperate phages

A viral reproductive stage where the virus’s DNA is being replicated using the host cell’s DNA. During its infection, the virus uses the host to help copy its DNA or genetic information, but it is not producing any proteins. ​

prions

A type of protein that can cause disease in animals and humans by triggering normally healthy proteins in the brain to fold abnormally. The scientific community had a hard time accepting it because some features of the diseases caused by _____ and viruses are similar. 

pandemic 

An epidemic that affects a wide geographic area. 

Illness, sex, stress, sunlight, and fatigue

What is the cause of herpes outbreaks?