introduction to bacteria

Question 1

what are the estimated types of bacteria in the human body

Answer 1

500 - 1000

Question 2

how can we describe bacteria

Answer 2

shape, size, colony shape size and colour, smell

Question 3

what are the two categories of cell shape

Answer 3

cocci and bacilli

Question 4

what shape are coccci

Answer 4

sphere

Question 5

what shape of bacilli

Answer 5

rods

Question 6

what are appendaged bacteria

Answer 6

group of bacteria that can change shape during their reproductive cycle

Question 7

when was the first grown bacteria

Answer 7

1887

Question 8

What is gram positive bacteria

Answer 8

thick peptidoglycan layer and no outer lipid layer

Question 9

what is gram negative bacteria

Answer 9

thin peptidoglycan layer and have an outer lipid membrane.

Question 10

what are phototrophs?

Answer 10

bacteria that can utilise light as an energy source

Question 11

what are chemotrophs

Answer 11

can only gain energy from chemical compounds

Question 12

what element do all bacteria require?

Answer 12

CO2

Question 13

obligate anaerobes will not survive when exposed to

Answer 13

oxygen

Question 14

what do extreme obligate anaerobes require

Answer 14

an abundance of o2

Question 15

what do facultative anaerobes thrive on

Answer 15

oxygen

Question 16

what is unique about aerotolerant anaerobes

Answer 16

they are indifferent in the presence of oxygen, they do not need oxygen to survive

Question 17

what are the four components of the growth curve?

Answer 17

lag phase, log phase, stationary phase, death/decline phase

Question 18

How do bacterial reproduce

Answer 18

binary fission

Question 19

what happens during the lag phase

Answer 19

cells are not diving but the cells are growing in size and synthesising proteins

Question 20

what happens during the log phase

Answer 20

bacterial cells are actively diving by binary fission and their numbers grow exponentially

Question 21

what happens during the stationary phase

Answer 21

when growth rate decreases, waste products accumulate and nutrients are gradually used and O2 is depleted.

Cells dying and cells dividing is equal causes a plateau

Question 22

what happens during the dead/decline phase

Answer 22

nutrients are exhausted and toxin waste accumulates. Bacterial cells die quicker than they divide

Question 23

what is an indirect method to measure the growth curve

Answer 23

turbidity of the culture by using a spectrophotometer. light wavelength is shown onto the sample. measures the amount of light that passes through.

Question 24

what is a direct method of measuring the growth curve

Answer 24

using CFU, the culture is diluted and small sample is poured onto a plate. We count the colonies