Prokaryotes Basic Structure

what are the structural differences between bacteria and eukaryotes

eukaryotes

• nucleus

• membrane bound organelles

• larger

• multiple linear chromosomes

• histone proteins

• cellulose or chitin cell wall

• 80s ribosome size

• reproduce by mitosis

bacteria

• no nucleus

• no membrane bound organelles

• small

• single circular chromosome

• no histone proteins

• 70s ribosome size

• free floating DNA

• reproduces by binary fission

why is studying prokaryotic cell structure important

Food production, Agriculture, Gut microbiota, disease, energy production (e.g. photosynthesis) and biotechnology

how are prokaryotes important in agriculture

• nitrogen fixation, producing fertiliser

• nutrient cycling

• animal husbandry and protein

what does gut microbiota mean

the community of microorganisms living in the gut

what is the importance of studying gut microbiota

• general wellbeing

• obesity

  • susceptibility to disease and mental health issues

roughly when did bacteria and archaea become distinctive

about 3.7 billion years ago

• tracked back to LUCA

what is the point of a cell

• carry out functions

• building blocks of life

  • pass down genetic information

structural differences between archaea and eukaryotes

archaea

• no nucleus

• no membrane bound organelles

• smaller

• single circular chromosome

• pseudopeptidoglycan cell wall

• branched hydrocarbons with ether bonds

• 70s ribosome size

• reproduction by binary fission

eukaryotes

• nucleus

• membrane bound organelles

• linear multiple chromosomes

• reproduction by mitosis

• 80s ribosome size

• unbranched fatty acids with ester bonds

• cellulose or chitin cell wall

• larger

structural differences between bacteria and archaea

bacteria

• peptidoglycan cell wall

• unbranched fatty acids with ester bonds

archaea

• pseudopeptidoglycan cell wall

• branched hydrocarbons with ether bonds

what are the 3 primary bacteria shapes

• rod

• coccus (egg shape)

• spirillum (corkscrew)

equation for surface area

4πr2

equation for volume

4/3πr3

what is one adaptation to increase surface area

folded membrane

how is sa:v a limiting factor for single celled organisms

if volume increases, the cell surface may be too small to match the inner cells demand

how is the cell membrane arranged

fluid mosaic model

which parts of a phospholipid is hydrophilic

the head

what is the affect of having unsaturated phospholipids on the membrane

becomes more permeable

what is the arrangement of a double membrane

two seperate membranes with a space between them

what makes a phospholipid unsaturated

1 or more double bonds

what are the types of unsaturated fatty acids

• monounsaturated

• polyunsaturated

what type of unsaturated fatty acids do eukaryotes have

polyunsaturated

what type of unsaturated fatty acid do prokaryotes have

monounsaturated fatty acids

what does flip-flop mean

when lipids move, flip or are modified

how often does ‘flip-flop- happen?

~ once a month

what properties of the cell enable it to survive in a harsh environment

• homeostatsis

• sodium-potassium pump

• cell wall

where are proteins within the cell membrane found if it is a double membrane

usually the outer membrane

where do peripheral membrane proteins sit

on the outside

where are integral membrane proteins found

imbedded in the membrane

what does chiral mean

can’t be composed on mirror image, it has a set structure

what prokaryote has a chiral membrane

archaea

what are the 3 main roles of a cell membrane

1. permeability barrier

2. anchor to imbed proteins

   1. energy production/conservation

what are aquaporins

tubes which allow the movement of water (which may have macro and micro molar nutrients) in and out a cell

what is the main problem of aquaporins

water will travel into the cell by osmosis leading to lysis

what is the advantage of eukaryotes having subcellular compartments

• creates different environments for different functions and biochemical reactions (e.g. pH levels)

• allows greater complexity