Intro to Bacteria 3

Question 1

What is bacterial metabolism?

Answer 1

It is the uptake of nutrients by the cell

Question 2

What is passion diffusion?

Answer 2

molecules move from a region of high concentration to one of low concentration
No energy required
O2, CO2, H2O

Question 3

what is facilitated diffusion?

Answer 3

No energy required, requires a gradient
It is selective, use of a carrier protein (permeases)
porins

Question 4

What is active transport?

Answer 4

the transport of solute molecules to higher concentration or against a concentration gradient
metabolic energy input
importers mediate the uptake of nutrients into the cell
exporters or effluxers pump toxins and drugs out of the cell

Question 5

Iron uptake

Answer 5

microorganisms require iron for use in cytochromes and many enzymes
little free iron available
many bacteria and fungi secrete siderophores (low molecular weight iron binding molecules)
iron siderophore complex binds to siderophore receptor protein
iron is transported inside the cell

Question 6

What is metabolism?

Answer 6

the sum total of all chemical reactions occurring in a cell

Question 7

what is catabolism?

Answer 7

molecules are reduced in complexity and free energy is made available

Question 8

what is anabolism?

Answer 8

involves the use of free energy to increase the complexity of molecules

Question 9

Fermentation

Answer 9

no oxygen
organic compound :e- acceptor
inefficient
range of end products produced
organisms in gut

Question 10

respiration

Answer 10

aerobic or anaerobic
aerobic especially efficient

Question 11

Salmonella metabolism

Answer 11

colonic bacteria produce hydrogen sulfide which combines with caecal mucosa to form thiosulfate
salmonella adapts to metabolise tetrathionate, large amounts in the gut
coliforms reduced

Question 12

Primary bacterial identification

Answer 12

gram reaction, shape
oxidase and catalase reactions
growth or its absence on MacConkey agar

secondary biochemical tests reflect bacterial metabolism
molecular tests

Question 13

How do bacteria grow?

Answer 13

they grow on solid media as colonies, originating from a single mother call and are all genetically identical
how the grow is useful in identification

Question 14

cultural characteristics

Answer 14

colonial morphology

Question 15

PCR

Answer 15

DNA of organism amplified using primers for the region of interest

Question 16

conventional pcr

Answer 16

product detected on a gel, not quantitative

Question 17

real time pcr

Answer 17

product detected in real time may be quantitative if standard curve generated