JALC BIO 226 Exam 1 Study Guide

JALC BIO 226

operon

cluster of prokaryotic genes controlled by a single promoter

mutation

change in the base sequence of existing DNA- result of either DNA damage or errors in replication.

conjugation

horizontal gene transfer mediated by a plasmid- requires physical contact between the donor and recipient of the transferred DNA.

transformation

horizontal gene transfer where bacteria take up free-floating DNA from their environment.

transduction

horizontal gene transfer where DNA is carried by a phage.

vertical gene transfer

inheritance of genes from parents during reproduction

horizontal gene transfer

in prokaryotes, spreading of DNA to an unrelated organism of the same generation (not reproduction)

Jacob and Monod

The first people to describe gene regulation (of the lac operon of E. coli)

start codon

Signal that controls the beginning of translation.

codon

Any of the 64 possible 3-base sequences (in mRNA). Each one specifies either an amino acid or a STOP to translation.

stop (nonsense) codon

one of 3 signals that can bring an end to translation

Bruce Ames

Invented a test that bears his name that is used to identify mutagens

mutagen

a chemical (such as heterocyclic amines) or physical factor (such as radiation) that increases the rate of mutations above the spontaneous level.

Salmonella

Bacteria used to identify mutagens in the Ames test.

cancer

Most mutagens raise the risk of this type of human disease.

transduction

type of horizontal gene transfer responsible for creating E. coli O157:H7 and other rapid pathogen evolution.

conjugation

type of horizontal gene transfer most responsible for transferring antibiotic resistance from one bacterial species into new ones.

transformation

An artificial form of this is used to introduce recombinant DNA into cells in genetic engineering.

Frederick Griffith

FIrst to describe horizontal gene transfer (transformation, specifically)

Avery, McLeod, McCarty

In the context of studying transformation, these 3 demonstrated that genes are made of DNA.

silent (mutation)

A base substitution mutation that does not change the sequence of the encoded polypeptide- mutated codon stands for same amino acid as the original one.

nonsense

A base substitution mutation that caused a shortened, but otherwise normal polypeptide to be produced. The mutation produces a premature stop codon within the gene.

frameshift

An insertion or deletion mutation will have this effect, where, from the site of the mutation onwards, virtually every amino acid encoded is altered.

missense

A base substitution mutation that changes only one amino acid in the encoded polypeptide.

base substitution

mutation that does not change the length of the gene, but replaces one base with another

insertion or deletion

two types of mutations that have similar causes and effects, that change the length of a gene by adding or removing bases.

regulation of gene expression

changes phenotype but not genotype- reversible

mutation and horizontal gene transfer

2 processes that change genotype and possibly phenotype\-- not reversible.

natural selection

The observation that a gene or version of a gene that improves reproductive success / survival becomes more common over generations. One force that causes evolution (not the only one)..

repression

when the presence of a substance prevents expression of the gene (glucose, for the lac operon)

spontaneous

mutations that occur due to normal cellular processes that damage DNA or cause replication errors- not caused by any identifiable environmental factor.

mutation

process that can produce a new version of a gene, or a gene with a new function.

horizontal gene transfer

process that can move a gene from one type of bacteria into another.

horizontal gene transfer

This type of process can move drug resistance genes from harmless microbiota bacteria where they were selected by antibiotic treatment into pathogens that enter the body months later.

plasmid

a small, circular piece of DNA separate from the bacterial chromosome. It replicates independently of the chromosome and often carries "auxiliary" genes that are occasionally useful.

colonies

a mutagen will cause an increase in the number of these in an Ames test

selection

The term for the process by which a course of antibiotics kills off most of the bacteria in the patient, allowing the rare cells that contain a drug resistance gene to survive, grow, and "take over" the environment. Called antibiotic \__________________________

Which type of microorganism is correctly matched to its description?

Bacteria- Cells with no nuclei, but almost all have peptidoglycan

What are protozoans?

Simple single celled prokaryotic microorganisms without cell walls

What are helminths?

Parasitic multicellular animals; also called "parasitic worms"

What is biotechnology?

The human use of microorganisms or their components to perform useful tasks or create useful products (food, drugs, bioremediation)

Which microorganism is NOT correctly described?

Escherichia coli- Is found mainly on human skin

Which is a correctly written scientific name?

Spongiforma squarepantsii (underlined)

Match the correct microbiologists to their accomplishments.

1. Pasteur- Proved biogenesis

2. Von Leeuwenhoek- First to see live microbes that he called "animalcules"

3. Koch- Matched particular pathogens to specific diseases

4. Berg- Created the first hybrid or "recombinant" DNA

5. Jenner- First European doctor to use a vaccine

Which microbiologist discovered the first antibiotic?

Flemming

What did the clinical case (Andrea) in chapter 1 demonstrate about MRSA?

Someone who is sick with it may have acquired it through contact with a person who seems healthy.

Which description below would be true about sodium (Na)? Its atomic number is 11, and its atomic mass is 23.

An uncharged atom must have exactly 11 electrons.

What is an isotope?

Term for forms of the same element that have different atomic masses

Which type of bond is NOT correctly described?

Hydrogen- These are not very important in biology because they are so weak

Water has a strong tendency to form...

Hydrogen bonds.

Which functional group is correctly described or identified?

Methyl (-CH3)

How are macromolecules formed?

A condensation or dehydration reaction.

Which is true about a solution with a pH of 2?

It is 10 times more acidic than a solution with a pH of 3.

Which large molecule type is NOT correctly described?

Lipids- The saturated ones have more double bonds in their fatty acid subunits than the unsaturated ones do

Which macromolecule is correctly described?

Cellulose- This polymer of glucose is not broken down by animal enzymes, but can be used as food by animals such as cattle because of the bacteria they carry in their rumen

Amylose- Beans are rich in this starch that feeds beneficial microbes in the human colon, but cannot be easily hydrolyzed by human enzymes

Glycogen- Polymer or glucose used for storage by humans and some bacteria

Amylopectin- Polymer of glucose that can be broken down by human digestive enzymes in the small intestine and is absorbed by human cells to use as an energy source

Which of the types of microorganisms contains sterols in its cell membrane?

Most types of eukaryotes

Which is true of prokaryotes?

Cells contain the smaller size ribosomes (70s)

Which is true of eukaryotes?

Their cells are larger and more complex than prokaryotes.

Biofilms

May contain multiple species of bacteria

What are finbriae?

Thin protein "hairs" that attach cells to other cells or to surfaces

What does streptococcus bacteria look like?

Long circle lines (peas in a line)

Gram positive bacteria have...

Teichoic acids

Peptidoglycan

is the target of drugs such as pennicilin and body defenses such as the lysozyme found in tears and saliva

Which description is NOT true of gram negative bacteria?

They have a thicker cell wall than gram positive bacteria

One of the most useful pieces of information about a bacterial infection is the pathogen's gram reaction. What is one of the reasons that this information helps in dealing with an infection?

Some antibiotics are effective only against gram positive, but not gram negative bacterial infections

Which structures are correctly described?

Ribosomes: Structures in cells that build proteins

Mitochondria: Generates ATP using energy from "organic" food molecules

Lysosomes: Contain digestive enzymes that help white blood cells to kill bacteria

Chloroplasts: Generate ATP using light energy

Which of the following is true of endospores?

They can survive for millions of years

Which is NOT true about plasma cell membranes?

They allow most substances such as salts to move freely from low to high concentration through the membrane

Which is NOT correctly described?

Osmosis- Involves the active transport of water through the membrane

Which is NOT true about the clinical case about the Klebsiella pneumoniae outbreak in the hospital?

This bacteria is gram positive, which is why it caused more problems in the patients

Which of the following is NOT true about endosymbiotic hypothesis?

It was disproven by the DNA found within chloroplasts and mitochondria

Which is true of the human microbiota?

E. coli is found mainly in the microbiota of the large intestine

What would prevent Koch's postulates from being fulfilled for a disease?

The pathogen cannot be grown in a laboratory

V. fiscerii grows in a specialized organ of the bobtail squid. THe squid secretes nutrients into the structure that feeds the bacteria. THe bacteria produce light that masks the squid's shadow as it hunts in shallow waters.

The best term used to describe this relationship is...

Mutualism

What is a secondary infection

opportunistic infection after a primary (predisposing) infection

Hospital acquired infections...

DONT always involve fomite transmission (fomite-objects)

Which is the stage in the course of an infectious disease when the patient first begins to experience mild symptoms?

Prodrome

Which is not correctly described?

All diseases caused by a microorganism are communicable

In 2012, a viral pneumonia was first identified in a number of older men who lived in or had recently traveled to the Middle East. The virus has been traced to camels, who, when infected, can develop mild symptoms themselves. The new disease is caller MERS (Middle East Respiratory Syndrome).

In the summer of 2018, an outbreak of 166 cases of MERS occurred in South Korea when a sick traveler returning from Saudi Arabia visited several clinics and hospitals seeking treatment. Almost all the cases occurred in health care providers and other patients in the facilities the traveler visited.

QUESION: Which of the following is NOT true about this disease from the description given here?

A. MERS is endemic to South Korea