Prokayotic And Eukaryotic Flashcards
What’s a prokaryote?
- single celled organisms with simple/primitive cells
What features of a cell are prokaryotes only?
- plasmids
- mesosomes
- pili
- slime capsule
- peptidogylcan cell wall
- circular DNA
What is the mesosome? What is it the site of in prokaryotic cells?
- infolding of the cell membrane
- site of respiration (because prokaryotes don’t have mitochondria)
What is the role of pili in prokaryotes?
- to adhere to surfaces
What is the role of flagella?
- rotates to allow movement
What are ribosomes in prokaryotes called? Are they bigger or smaller than ribosomes in eukaryotes?
- 70s ribosomes
- smaller
What are plasmids?
- rings of DNA
What do plasmids contain?
- survival genes
Can plasmids be exchanged between bacteria?
- yes
What is the nucleoid?
- the area of the cytoplasm that contains the DNA
What do prokaryotes not have, but eukaryotes do?
- membrane-bound organelles
What are eukaryotic cells?
- complex cells
- cells that contain a nucleus and other membrane bound organelles
- animals, plants, fungi
What is a lysosome?
- a vesicle containing digestive enzymes
What is the role of a smooth endoplasmic reticulum?
- to take in lipids and modify them
What is the nucleolus?
- a dense region of DNA
What is the role of a rough endoplasmic reticulum?
- to take in proteins from ribosomes and modify them
What organelle is the site of protein synthesis?
- ribosomes
What genetic materials do eukaryotes have?
- linear DNA
What’s the difference between a prokaryotic cell wall and a eukaryotic cell wall?
- p: peptidoglycan
- e: cellulose (plants) or chitin (fungi)
What cell walls do fungi and plants have?
- fungi: chitin cell wall
- plants: cellulose cell wall
What’s the role of the capsule?
- protection against toxins and antibiotics
What is chromatin?
- linear uncondensed DNA
When does chromatin condense to form chromosomes?
- just before mitosis
Where are proteins synthesised to form mRNA?
- ribosomes
Where are ribosomes found?
- free in the cytoplasm or attached to the rough endoplasmic reticulum
Do ribosomes have a membrane?
- no
What is the lysosome made by?
- golgi apparatus
What type of enzymes do lysosomes contain?
- digestive enzymes
What type of ribosomes do mitochondria contain?
- 55s ribosomes
What’s the space in between the inner membrane and outer membrane of mitochondria called?
- inter membrane space
What’s cristae in mitochondria?
- infoldings in the inner membrane to increase surface area
What’s the function of mitochondria?
- aerobic respiration
What does the matrix in the mitochondria contain?
- 55s ribosomes
- enzymes for respiration
- circular DNA
Are mitochondria prokaryotic or eukaryotic?
- eukaryotic
What is the function of the centrioles? what cellss are they found in?
- make spindles that separate chromosomes during cell division
- animal
What are centrioles made of?
- hollow protein cylinders (micro tubules)
Centrioles are found in pairs. At what degree do they cross?
- crossed at 90 degrees
What ribosomes is the RER covered in? what cells are they found in?
- 80s
- animal and plant
What is the RER often attached to?
- the nuclear envelope
what makes up the RER and the SER?
- flattened single membrane sacs filled with fluid (cisternae)
What’s the function of the RER?
- to fold and modify the proteins made by the ribosomes
- to package then into transport vesicles
Does the SER have ribosomes attached?
- no
What is the function of the SER?
- lipid synthesis
- storage and package them into transport vesicles
What are the identifiable features of the golgi apparatus?
- surrounded by vesicles
- cisternae decreases in size (wifi)
What’s the function of the golgi apparatus?
- modifies proteins and lipid made in the SER/RER and packages them into secretory vesicles
- makes lysosomes when it packages digestive enzymes
What’s the nuclear envelope?
- the double membrane of the nucleus
What is translation?
- when amino acids in the cytoplasm are joined together to form a primary protein on the ribosomes
What’s protein trafficking?
- the pathway of amino acids from incorporation into a protein to secretion out of the cell
What’s the first step of protein trafficking?
- amino acids are joined to form a protein on the ribosomes during translation
What’s the second step of protein trafficking?
- protein is modified in the RER (folded and can have carbs added)
What’s the third step in protein trafficking?
- RER pinches off and packages the protein into a transport vesicle
What’s the fourth stage in protein trafficking?
- the transport vesicle moves towards and fuses with the golgi apparatus
What’s the fifth stage of protein trafficking?
- modified further
What’s the sixth stage of protein trafficking?
- golgi apparatus pinches off and packages protein in to a secretory vesicle
what’s the last stage of protein trafficking?
- secretory vesicle moves towards and fuses with cell membrane
- proteins then secreted by exocytosis
In a plant cell, what is a cell wall made out of?
- cellulose
What’s the role of the cell wall?
- supports plant cell
- rigid structure
- fully permeable
What joins cellulose chains together?
- hydrogen bonds
What’s the middle lamella made out of? (plant cell)
- calcium pectate
What does the middle lamella do?
- stuck two adjacent cells together
- increases stability of the tissue being formed
What are plasmodesmata?
- channels in the cell wall that connect two adjacent cells
What is the plasmodesmata filled with? what does it allow?
- a stream of cytoplasm
- allow transport of substances and communication between cells
What are pits?
- where the secondary cell wall is broken down
What do pits contain?
- plasmodesmata
When a pit of one cell aligns with a pit of an adjacent cell, what does this allow?
- transport of substances between cells
In chloroplasts, how are grana linked together?
- lámela
What are lamella in chloroplasts?
- thin sheets of thylakoid membrane
What’s stroma in chloroplasts?
- fluid filled matrix where enzymes for photosynthesis are
What are amyloplasts?
- membrane bound organelles containing starch granules
What do amyloplasts do?
- convert starch back to glucose when needed
The vacuole in a plant cell has a membrane with a specific name. What is it called?
- the tonoplast
What does the vacuole do/contain?
- keeps cell turgid which helps regulate osmotic gradients within the cell
- contains cell sap (water, enzymes, minerals and waste products)
