prokaryotic cells Flashcards
(12 cards)
write a sentence to compare eukaryotic and prokaryotic cells?
eukaryotic cells are larger and have a nucleus bounded by a nuclear envelope
whereas prokaryotic cells are smaller and have no nucleus or nuclear envelope
explain how DNA differs between eukaryotic cells and prokaryotic?
euk- DNA is associated with proteins called histones, DNA is linear, DNA in nucleus
pro- DNA is not associated with proteins, some DNA may be in form of circular strand called plasmids
how do membrane bound organelles compare in eukaryotic and prokaryotic cells?
pro- no membrane bound organelles
euk- many such as mitochondria
compare ribosomes in eukaryotic and prokaryotic cells?
smaller in pro (70S)
larger in euk (80S)
what is the difference in cell walls between prokaryotic and eukaryotic cells?
pro- made of murein (peptidoglycan)
euk- made mostly of cellulose where present (or chitin for fungi)
what additional features do some prokaryotic cells have?
-flagellum
-capsule
-plasmids
which cell is generally bigger- prokaryotic or eukaryotic?
eukaryotic
what does a capsule do?
protects bacterium from other cells and helps groups of bacteria stick together for further protection
what do plasmids do?
possesses genes that may aid the survival of bacteria in adverse conditions e.g. produces enzymes that break down antibiotics
what is the process prokaryotic cells divide by?
binary fission
describe the process of binary fission? (3)
-the circular DNA molecule replicates and so do the plasmids
-the cell membrane begins to grow between the two DNA molecules and starts pinching inwards, dividing the cytoplasm into two
-new cell membranes form between the two molecules of DNA, dividing the original cell into two identical daughter cells- each with a singular copy of the circular DNA and a variable number of copies of plasmids
what is an equation for calculating the number of cells after divisions?
2^n
where n is number of divisions
