study guide chapter 5, 6, 13

what is the purpose of catabolic degradation of glucose?

to provide chemical energy in the form of ATP and NADH

identify the 3 pathways required for the total aerobic breakdown of glucose

glycolysis, Krebs cycle, respiratory chain

where does glycolysis, Krebs cycle and respiratory chain occur?

mitochondria

what are coenzymes?

organic molecules usually vitamins

identify the components from which coenzymes are synthesized

name and state the function of 3 coenzymes

(niacin) nicotinamide adenin dinucleotide (NAD+) - carrier of reducing power

flavin adenine dinucleotide (FAD) - carrier of reducing power

coenzyme A - formation of acetylene-CoA in citric acid cycle and beta-oxidation

how many ATP are produced as a result of glycolysis?

6

where does glycolysis occur?

cytoplasm

what are the staring and end products of glycolysis?

starts with 1 molecule of glucose and ends with 2 pyruvate molecules

what are the many fates of pyretic acid?

aerobic, anaerobic and fermentation

coenzyme A

formation of acetyl-CoA in citric acid cycle and beta-oxidation

acetyl coenzyme A

what waste products are generated in the kreb cycle?

(3) Co2

how many ATP are generated in the kreb cycle?

2

Identify starting and end products of the kreb’s cycle

starts with 2 pyruvate and ends with 3NADH, FADH2, 2CO2, ATP

which and how many coenzymes are reduced in the kreb’s cycle?

2NADH2, 1NADH2, 1FADH2

why are the reactions of the electron system termed oxidative phosphorylation?

because the proton gradient is created by the oxidation of carriers in an electron transport chain

what waste product is generated in the ets?

water

identify the final electron acceptor in fermentation

organic molecule

identify the final electron acceptor in aerobic respiration?

O2

identity the final electron acceptor in anaerobic respiration?

non oxygen electron acceptors

how can oxidation of a substrate proceed without oxygen

when it loses an ion

using the concept of fermentation, describe the microbial mechanisms that cause milk to sour

fermentation creates lactic acid which causes milk to sour

list 3 products that are produced fermentation reactions

alcohols, acids, gases

what is the commercial importance of fermentation reactions?

converts sugars into alcohol

amphiboles

reactions that can process in either direction-towards catabolism or toward anabolism

what are the 6 major categories of enzymes

hydrolase, isomerases, liagases or polymerases, oxidoreductases, transferases

hydrolase

catabolizes molecules by adding water in a decomposition process known as hydrolysis

isomerases

rearrange atoms within a molecule but do not remove or add anything

ligases or polymerases

join to molecules together

lyases

split water molecules without using water in the process

oxidoreductases

removes electrons from (oxidize) or add electrons to (reduce) various substrates

transferases

transfer functional groups between molecules

what is the biological importance of fermentation reactions?

allows glucose to be broken down to make ATP due to the recycling of NADH to NAD+

explain how ATP is generated by chemiosmotic coupling on the cristae of the mitochondria

ATP is synthesized utilizing energy released by the flow of ions down their electrochemical gradient across a membrane

how do organisms die from cyanide poisoning?

cyanide prevents the cells of the body from using oxygen

what is proton motive force?

potential energy of a proton gradient

metabolism

all chemical and physical workings of a cell

catabolism

degradative; breaks the bonds of larger molecules forming smaller molecules; releases energy

anabolism

biosynthesis; process that forms larger macromolecules from smaller molecules; requires energy input

coenzymes

certain organic molecules

apoenzymes

proteins in combinations of both protein and nonprotein portions

aerobic metabolism

series or enzyme-catalyzed reactions in which electrons are transferred from the fuel molecules (glucose) to oxygen as a final acceptor

why are carbohydrates required for bacterial growth?

used as a nutrient for growing microbes (ex: polysaccharides, glucose, sugars); main energy source for microbial growth and metabolism

why do all living organisms require a source of nitrogen?

nitrogen is the part of the structure of amino acids, proteins, DNA, RNA, and ATP for heterotrophs and must be combined with carbon to synthesis amino acids, etc. for living things

identify the 4 phases of a bacterial growth curve

lag phase, log (exponential) phase, stationary phase, death (decline) phase

lag phase

cells are adjusting to their new environment; most cells do not reproduce immediately but instead actively synthesize enzymes to utilize novel nutrients in the medium

log (exponential) phase

the bacteria synthesize the necessary chemicals for conducting metabolism in their new environment and then enter a phase of rapid chromosomes replication, growth, and reproduction

stationary phase

the number of dying cells equals the number of cells being produced

death (decline) phase

cells die at a faster rate than they are produced

in which phase of bacterial growth curve are bacteria most easily killed?

death (decline) phase

in which phase of bacterial growth curve are bacteria most easily transferred?

stationary phase

in which phase of the bacterial growth curve do you expect most metabolic inhibitors be most effective?

log (exponential) phase

autotrophs

organisms that utilize an inorganic source of carbon as their sole source of carbon; they make organic compounds from CO2 and thus need not acquire carbon in organic compounds from other organisms

heterotrophs

catabolize organic molecules (such as proteins, carbohydrates, amino acids, and fatty acids) they acquire nutrients from other organisms

what is the habitat of a strict saprobe?

exist strictly on dead organic matter in soil or aquatic reservoirs; strict decomposers

what is the habitat of a facultative parasite?

natural habitat is soil/aquatic and live host

enriched media

bacteria that are present in small numbers may be overlooked on a streak plate or overwhelmed by faster growing more abundant strains

selective media

typically contain substances that either favor the growth of particular microorganisms or inhibit the growth of unwanted ones

differential media

formulated such that either the presence of visible changes in the medium or differences in the appearance of colonies help microbiologist differentiate among all kinds of bacteria growing on the medium

if an egg salad sandwich sitting in a warm car for 4 hours develops 40,000 bacterial cells, how many more cells would be present after 1 more hour of incubation?

80,000 more

how can osmotic pressure be used to preserve foods?

removal of water and addition of salt/sugar to some foods, such as meats, creates a solute-rich environment where osmotic pressure draws water out of microorganisms, thereby delaying their growth

how does osmotic pressure affect microbes?

microbes need a certain osmotic pressure to maintain integrity/get nutrients

how can you explain why unopened milk will spoil, even in the refrigerator?

the milk does contain microorganisms and the cold temperature is bacteriostatic, it is simply slowing the growth of microorganisms not inhibiting it

mutualism

both benefit and are dependent on each other

commensalism

one member benefits the other member is neither harmed for unharmed

parasitism

parasite is dependent and benefits; host is harmed

how does heat kill microorganisms?

denatures their enzymes/proteins; permanently alters their protein/enzyme structure

how do cold temperatures effect microbial growth?

slows the growth of cultures and microbes in food/perishable material during processing/storage

describe the basic components of a typical virus

nucleic acid (DNA or RNA), capsid, phospholipid membrane (envelope), protein coat

difference between “naked” nucleocapsid and enveloped nucleocapsid

“naked” are typically more virulent than enveloped viruses; enveloped viruses are more fragile than “naked” ones

what is a capsid and what is the function?

capsid- a protein coat surrounding the nucleic acid core of a virion; provides protection for viral nucleic acid

what is a nucleocapsid?

a viral nucleic acid and its capsid together

how are viruses classified?

type of nucleic acid, presence of an envelope, shape and size

what are virus families?

ends in viridae

how are virus genomes different from the genomes of all other species?

whereas the genome of every cell is double stranded DNA, a viral genome is either DNA or RNA

what is the difference between positive and negative sense of RNA genomes?

positive-sense (+RNA) is equivalent to mRNA; that is, it instructs ribosomes in protein translations

negative-sense (-RNA) is complementary to mRNA; it cannot be directly translated

compare and contrast lytic infections and lysogenic infections.

lytic infections - replication cycle of a virus usually results in the death and lysis of the host cell

lysogenic infections - some have modified replication cycle in which infected host cells grow and reproduce normally for many generations before they lyse

both replications of bacteriophages

can a lysogenic infection be lytic?

yes

what occurs during viral lysogen?

infected host cells grow and reproduce normally for generations before they lyse

what is lysogenic conversion

results when phages carry genes that alter phenotype of bacterium

compare and contrast bacteriophage infective cycles with those of animal viruses

same basic replication pathway

differences results from: presence of envelope around some viruses, eukaryotic nature of animal cells, lack of cell wall in animal cells

what are oncoviruses?

a viruse that can cause cancer

list 2 oncoviruses

examples of viruses that do not obey the rules of viruses being host and tissue specific

West Nile virus and HIV

prions

infectious agents of mammals that differ from other infectious agents because they lack nucleic acid

satellite viruses

the replication cycle “revolves around” a helper virus

how is AIDS diagnosed?

blood test

what is the difference between infection with HIV and AIDS?

HIV is a virus that weakens your immune system. AIDS is a condition that can happen as a result of an HIV infection when your immune system is severely weakened

what are virus families?

the basic unit of biologic classification of viruses; ends in viridae

what is the difference between herpes simplex I and herpes simplex II

herpes simplex I oral

herpes simplex II genital

what disease are caused by Varicella-Zoster Virus (VZV)?

chicken pox and shingles

why is there so much genetic variability among the influenza viruses?

where do herpes simplex I & herpes simplex II remain dormant?

I - in the neurons of the 5th cranial: trans nerves

II -in the neurons of the lumbosacral spinal nerve trunk ganglia

how is diseases caused by EBV different in the developed world and the under-developed world?

developed: EBV is mononucleosis, college age pop most vulnerable

underdeveloped: EBV is burrito lymphoma in Africa & is associated with malaria

why is there so much genetic variability among influenza viruses?

their glycoprotein spikes, hemagglutinin (H) & neuraminidase (n), frequently undergo genetic changes; undergo antigenic drifts and antigenic shifts

why are cases of the flu linked to secondary bacterial infections especially Staphylococcus aureus?

because the weakened host defenses by influenza N spike predispose patients to secondary bacterial infections, especially pneumonia caused by Streptococcus pneumonia & Staphylococcus aureus

are antibiotics effective against viral infections?

antibiotics cannot kill viruses because bacteria and viruses have different mechanisms and machinery to survive and replicate. The antibiotic has no “target” to attack in a virus

explain why a physician might prescribe antibiotics during a virus infection

they prescribe antibiotics if the viral infection can make you more vulnerable to getting bacterial infections

how are virus infections routinely detected and diagnosed?

genetic analysis, serological testing for antibodies, through signs & symptoms, WBC profile examination