Prokaryotic (and Eukaryotic) cells Flashcards
prokaryotic cells
-make up single-celled prokaryotic organisms
-smaller than eukaryotic cells
-cells arise from other cells by binary fission
-don’t have membrane-bound organelles
eukaryotic cells
-make up complex eukaryotic organisms
-larger than prokaryotic cells
-cells arise from other cells by mitosis or meiosis
-have membrane-bound organelles
animal cell organelles
-mitochondria
-ribosomes
-ER
-golgi
-lysosomes
-nucleus
plant cell organelles
-vacuole
-chloroplasts
-cell wall
-all the organelles found in animal cells too
algal cell organelles
-exactly the same as for plant cells
fungal cell organelles
similar to plant cells, but:
-they have no chloroplasts
-cell wall is made from chitin instead
-they can be multicellular
structure of the nuclear envelope
-a double-membrane structure with lots of pores
-the inner and outer membranes are both phospholipid bilayers
function of the nuclear envelope
-its pores control the passage of ions, molecules and RNA between nucleoplasm and cytoplasm
structure of the nucleus
-has the nucleoplasm (semi-solid fluid) where we find chromatin and the nucleolus
-contains linear chromosomes made up of DNA (only in eukaryotes)
-has a nucleolus (plural is nucleoli)
function of the nucleus
-controls cell activity
-the DNA it contains, has the instructions for protein synthesis
-ribosomal RNA is joined together with associated proteins in the nucleolus to assemble the ribosomal subunits
structure of the nucleolus
-the largest sub-structure in the nucleus
-made from proteins like RNA, and DNA
function of the nucleolus
-the site where ribosomes are made
-has secondary roles like immobilising proteins and forming signal recognition particles
structure of mitochondria
-oval-shaped, double-membrane organelles that have their own ribosomes and DNA
-each membrane is a phospholipid bilayer embedded with proteins
-inner membrane has folds called cristae
-mitochondrial matrix is the area surrounded by the cristae
-the matrix contains enzymes used for respiration
function of mitochondria
-they make ATP via aerobic respiration
what does ATP stand for?
adenosine triphospate
function of chloroplasts
-carry out photosynthesis to make food (sugars) for the plant
structure of chloroplasts
-they have their own DNA, ribosomes and are double-membrane organelles
-thylakoids are the stacked, fluid-filled membrane sacks (found in inner-membrane)
-each stack of thylakoids is called a granum (plural is grana)
-grana is linked by lamellae, which are flat, thin parts of thylakoid membrane
-the fluid enclosed by the inner membrane that surrounds the grana is called stroma
structure of the golgi apparatus
a series of flattened membranous sacs
function of the golgi apparatus
-transport vesicles are made from the RER and fuse with the golgi apparatus
-the transport vesicles empty proteins and lipids into the lumen of the golgi apparatus
-as the proteins and lipids travel through the golgi, they are sorted packaged and tagged so that they can be sent to the right place
structure of golgi vesicles
-they are membrane-bound and fluid-filled, and found in the cytoplasm
-lysosomes are a type of golgi vesicle
-small and round
function of golgi vesicles
-they store and transport modified proteins and lipids from golgi apparatus to target cells
-e.g. lysosomes - which contain enzymes called lysozyme
-lysozymes aid the breakdown of proteins, polysaccharides, lipids, nucleic acids, and old organelles
structure of ribosomes
-can either be floating in cytoplasm or attached to the cytoplasmic side of ER
-small organelles made of protein sub-units which means they are not covered by a membrane
function of ribosomes
-in charge of protein synthesis
structure of the ER
-a series of interconnected, membranous sacs and tubules
-its membrane is a phospholipid bilayer embedded with proteins
-SER has no ribosomes
-RER does have ribosomes
