Microbiology exam 2 Kelli Roberts chapter 5,6,7

Selective

Mannitol salt agar

Deferential and selective

McConkey agar

Transcription of prokaryotes occurs in

Nucleoid

What happens in conjugation?

One bacterium with F+ plasmid makes sex pillus that attaches to another bacterium. The plasmid can replicate and be sent, or just be sent on its own. F+ confers ability to make a sex pillus.

Transformation

One of conclusive pieces of proof that DNA is genetic material. Cells that take up DNA are competent. Results from alterations in cell wall and cytoplasmic membrane that allow DNA to enter cell.

Specialized transduction

Only certain donor DNA sequences are transferred

Horizontal gene transfer

Organisms replicate their genomes and provide copies to descendants. Donor cell contributes part of genome to recipient cell.

Hyperthermophiles

Organisms that grow in extremely high temperatures (90 degrees C)

Final electron acceptor for aerobic respiration is

Oxygen

What happens in translation?

Process in which ribosomes use genetic information of nucleotide sequences to synthesize polypeptides. Participants in Translation: Messenger RNA,Transfer RNA, Ribosomes and ribosomal RNA.

Transcription

RNA polymerase seperates DNA strands and uses one of the strands as a template to assemble nucleotides into a complementary strand of RNA.

What happens in repressible operon?

Repressible operons are transcribed continually until deactivated by repressors (Tryptophan operon).

aerobic respiration

Respiration that requires oxygen

Ttype of RNA are involved in translation?

Ribosomal RNA (rRNA), messenger RNA (mRNA) transfer RNA (tRNA)

Termination

Ribosome reaches the stop codon; Release factors bind to aminoacyl site; Ribosome subunits break free.

Electron Transport Chain

Series of redox rxns that pass electrons from one membrane bound to another then passed to electron acceptor. Energy is used to pump protons across membrane. The final electron acceptor is oxygen. 34 ATP molecules from one glucose at the end of ETC.

Which stage of respiration is pyruvic acid?

Stage 2 the Krebs cycle where glycolysis produces two molecules of pyruvates.

What happen in fermentation?

The basic purpose of fermentation is to regenerate oxidizing agent NAD+ required for Glycolysis. During fermentation pruvate is reduced, NADH is oxidised, NAD+ is reduced and 2 ATP molecules are formed at end of the fermentation

Translation

The second phase of protein synthesis. It follows transcription in which the information in DNA is rewritten into mRNA

What happen in reduction?

The substance gains an electron in a chemical reaction and become more negative

What happen in oxidation?

The substances lose an electron in a chemical reaction and become more positive/oxidized

What are the components found in a lac operon?

The three genes are: (1) lacZ, which encodes the enzyme β-galactosidase (which splits lactose into glucose and galactose); (2) lacY, which encodes lactose permease; and (3) lacA, which encodes a lactose transacetylase.

Generation time

Time/# of generation

Three types of horizontal gene transfer

Transformation,Transduction, Bacterial conjugation.

Silent mutation

When DNA message change but the message still code for the same amino acid.

Active site of an enzyme

Where substrates molecules bind and undergo a chemical reaction

Does pyruvic acid needs to be groomed?

Yes

Redox reaction

a chemical reaction that involves a transfer of electron between two substances

Three stages of cellular respiration

1. Synthesis of acetyl-CoA 2.Krebs cycle (citric acid cycle) 3. Final series of redox reaction (electron transport chain)

Transduction steps

1.Phage injects its DNA. 2.Phage enzymes degrade host DNA. 3.Cell synthesizes new phages that incorporate phage DNA and, mistakenly, some host DNA. 4.Transducing phage injects donor DNA. 5.Donor DNA is incorporated into recipient's chromosome by recombination.

Finding out number of cells

2n

How many electron carries are reduced In the Krebs cycle?

8

What happen in transductions?

A foreign DNA is introduced into a cell by a virus or viral vector. (doesn't require physical contact)

Chemiosmosis

A process by which a hydrogen pump pumps protons into the thylakoid's membrane. H+ passively flows through the ATP synthase which leads to the creation of ATP

What is the start signal for transcription and translation?

AUG

plasmid

An independent, circular, self-replicating DNA molecule that carries only a few genes

Anabolic reaction

Anabolic reaction uses the energy produce by catabolic reaction to synthesize larger molecules from smaller ones. Example when body form proteins by stringing together amino acids.

What is the final electron acceptor in anaerobic respiration?

Anaerobic respiration is the formation of ATP without oxygen. This method still incorporates the respiratory electron transport chain, but without using oxygen as the terminal electron acceptor. Instead, molecules such as sulfate (SO42-), nitrate (NO3-), or sulfur (S) are used as electron acceptors.

How is conjugation differ sexual reproduction?

Bacterial reproduction and sex are two separate processes. Bacteria reproduce by a process called binary fission. During binary fission, the DNA is replicated and the cell separates. Each daughter cell receives a complete genome. This process represents asexual reproduction as no exchange or reassortment of genetic information takes place. During sexual reproduction, genes are reshuffled to increase genetic diversity . Gene transfer in eukaryotes occurs when two germ line cells from parents merge to form a zygote. The zygote contains equal amounts of DNA from both parents. Gene transfer in bacteria is a one-way street in that a donor cell gives DNA to a recipient cell, but not vice versa.

non competitive inhibitor

Binds to allosteric site, changing shape of active site, rendering enzymes are useless

competitive inhibition

Block active site, stopping substrate from binding

Differential

Blood agar

Catabolism

Breaks down molecules, releases energy (exergonic)

missense mutation

Change a codon so that a different amino acid is created

What does semiconservative DNA replication mean?

DNA molecule separate and each strand is use as a template for the synthesis of a new strand.

In what direction do DNA replication take place?

DNA synthesis occurs only in the 5' to 3' direction. On the leading strand, DNA synthesis occurs continuously. On the lagging strand, DNA synthesis restarts many times as the helix unwinds, resulting in many short fragments called "Okazaki fragments.

Bacterial conjugation

Donor cell attaches to a recipient cell with its pilus. Pilus draws cells together. One strand of F plasmid DNA transfers to the recipient.The recipient synthesizes a complementary strand to become an F+ cell with a pilus; the donor synthesizes a complementary strand, restoring its complete plasmid.

What is/are the products of alcohol fermentation?

Ethanol and carbon dioxide

Where does FADH2 yield less ATP than NADH?

FADH2 electrons enter the electron transport chain at a lower energy level

Okazaki fragments

Fragments are short sequences of DNA nucleotides (approximately 150 to 200 base pairs long in eukaryotes) which are synthesized discontinuously and later linked together by the enzyme DNA ligase to create the lagging strand during DNA replication.

What is the significance of Frederick's Griffins experiments on genetics transformation? what happened? What did his work teach us?

Frederick Griffith looked at Pneumonia bacteria trying to figure out what made people die S (SMOOTH) strain - killed mice R (Rough) strain - mice lived If he heated the LETHAL strain first, the MICE LIVED The heat-killed bacteria were no longer LETHAL But if he mixed heat-killed LETHAL bacteria with live harmless bacteria, the MICE DIED When he looked inside dead mice, he found LIVE LETHAL bacteria! Somehow, the heat killed LETHAL bacteria passed their characteristics to the harmless bacteria. Griffith called this process TRANSFORMATION because one strain of bacteria had been changed permanently into another. His work showed us that genetic material could be passed between bacteria and cause a change.

Krebs Cycle (Citric Acid Cycle)

Great amount of energy remains in bonds of acetyl-CoA. Transfers much of this energy to coenzymes NAD+ and FAD. Occurs in cytosol of prokaryotes and in matrix of mitochondria in eukaryotes

What directions do ribosomes move?

In 5' to 3'

Where is majority of ATP generated in prokaryotic cells?

In the cytosol, or cell membrane

What happens in inducible operon?

Inducible operons must be activated by inducers (Lactose operon).

Transcription

Is the first step in the synthesis of protein from specific gene sequences

Product of lactic acid in fermentation

Lactate

Number of generation

Log (final)-log (initial)/0.301

Elongation

anticodon of the tRNA pairs with codon on mRNA; complementary base pairing; anticodon of the tRNA with methionine pairs with start codon; peptide bond forms between amino acids; ribosome moves along the mRNA by one codon; peptide bond forms between amino acids.

Transduction

carries random DNA segment from donor to recipient.

Psychrophiles

cold-loving can grow at 0oC, and some even as low as -10oC; their upper limit is often about 25oC

lag phase

phase in a growth curve in which the organisms are adjusting to their environment

Death phase

phase in a growth curve in which the organisms are dying more quickly then they are being replaced by new organisms

Log phase

phase in a growth curve in which the population is the most actively growing

Stationary phase

phase in a growth curve which new organisms are being produced at the same rate at which the older organisms are dyin

What happens in transformation?

process by which bacterial cells take up naked DNA molecules, and such DNA will be replicated by the bacteria along its own DNA, if the foreign DNA has an origin of replication recognized by the host cell DNA polymerases.

Substrate

the substance on which an enzyme acts

Conjugation

transfer of DNA between bacteria using a pilus

Krebs Cycle results in

• 2 molecules of ATP • 2 molecules of FADH2 • 6 molecules of NADH • 4 molecules of CO2

Stages of transcription and translation

• Initiation • Elongation • Termination

Synthesis of Acetyl-CoA results in

• Two molecules of acetyl-CoA • Two molecules of CO2 • Two molecules of NADH

Organisms that can grow with or without an oxygen are called what?

facultative anaerobe

Where does pyruvic acid come from?

from glycolysis in the cytoplasm.

Three phases of aerobic cellular respiration

glycolysis, krebs cycle, electron transport chain.

Mesophiles

grow in the moderate temperature range, from about 20oC (or lower) to 45oC. Human pathogenic causing diseases.

Thermophiles

heat loving 50o or more, a maximum of up to 70oC or more, and a minimum of about 20oC.

Initiation

mRNA binds to the small sub-unit of the ribosome; ribosome slides along mRNA to the start codon; anticodon of the mRNA pairs with codon on mRNA; complementary base pairing.

Amphibolic pathways

metabolic pathways that function in both anabolism and catabolism