Prokaryotes and their structure

Question 1

prokaryotes do NOT have mem bound nucleus ! they are split into 2 domains

Answer 1

bacteria and Archaea – which have much in common with eukaryotes as they do with prokaryotes. they are found in extreme env’s.

Question 2

what are autotrophs?

Answer 2

they supply their own food! they use CO2 as their sole source of carbon

Question 3

what are heterotrophs?

Answer 3

use preformed organic molecules as their carbon source. these organic molecules can come from dead or living sources.

Question 4

phototrophs?

Answer 4

use light as their energy source

Question 5

chemotrophs?

Answer 5

oxidation of organic or inorganic matter.

Question 6

nitrogen fixation

Answer 6

some bacteria are capable of fixing nitrogen. nitrogen fixation is the process by which N2 is converted to ammonia. most plants can’t use ammonia but another bacteria process nitrogen in a process called nitrification. - which creates nitrates from ammonia. nitrates are used by plants.

Question 7

instead of a nucleus what do prokaryotes have?

Answer 7

single, circular double stranded molecule of DNA. THIS MOLECULE is twisted into supercoils and is associated with histones in Archaea and with proteins that are diff from histones in bacteria.

Question 8

The DNA, RNA and protein complex in prokaryotes forms a structure that’s visible under light microscope called ?

Answer 8

nucleoid ! : also called a chromatin body.

the nucleoid is not enclosed by a membrane.

Question 9

what are the two major shapes of bacteria?

Answer 9

cocci and bacilli (rod)
also spirilla (helically shaped) and
spirochetes

Question 10

prokaryotes have ____ complex, mem bound organelles

Answer 10

no

Question 11

all living things have both ?

Answer 11

RNA and DNA

Question 12

Prokaryotic ribosomes are smaller then eukaryote ribosomes

Answer 12

50S and 30S subunit to form a 70S ribosome.

Question 13

prokaryotes may or may not have mesosomes. what are they?

Answer 13

invaginations of the plasma mem

Question 14

prokaryotes also have inclusion bodies

Answer 14

inclusion bodies are granules of organic or inorganic matter that may be visible under light microscope. they may or may not be bound by a single layer membrane.

Question 15

the thick capsule or slime layer (glycocalyx) secreted by bacteria onto their surface. the capsule can aid in attaching to host cells and may ?

Answer 15

protect the bacterium from immune cells such as phagocytes.