T2: Structure of Cells Flashcards
what do all eukaryotic cells contain?
nucleus
cell membrane
mitochondria
ribosomes
smooth/rough endoplasmic reticulum
golgi apparatus + golgi vesicles
lysozomes
what organelles are exclusive to plant cells?
chloroplasts
vacuole
cell wall
what do prokaryotic cells contain?
circular DNA (not associated with histones)
cell wall (murein)
smaller 70s ribosomes
a cytoplasm without membrane-bound organelles
some have plasmid DNA, a slime capsule and flagella
describe the structure and function of the nucleus
contains nucleoplasm
surrounded by a nuclear membrane and nuclear pores
(allow molecules to enter + leave the nucleus)
contains chromatin (DNA coiled around histones - chromosomes)
has a nucleolus, site of ribosome production
F: controls the cells’ activities by controlling transcription
describe the structure and function of the cell membrane
a phospholipid bilayer
F: allows movement of substances in and out of the cell
describe the structure and function of the mitochondria
double membrane - inner highly folded to form cristae
contains a fluid called matrix - contains respiratory enzymes
mitochondrial DNA and ribosomes also found in the matrix
F: the site of aerobic respiration, produces ATP for the cells processes
describe the structure and function of the ribosomes
small free floating organelle, also attached to the RER
F: site of protein production
N - 80s found in eukaryotic cells
70s found in prokaryotes, mitochondria and chloroplasts
describe the structure and function of the rough endoplasmic reticulum (RER)
consists of sheets of membranes (cisternae) enclosing fluid filled space, covered in ribosomes
F: folds and processes proteins made at the ribosomes
describe the structure and function of the smooth endoplasmic reticulum (SER)
cisternae enclosing a fluid filled space without ribosomes
F: produces and processes lipids
describe the structure and function of the golgi apparatus and vesicles
a group of fluid filled membrane sacs
vesicles seen at the edge
F: processes and packages new lipids and proteins
makes lysozomes
vesicles store and transport proteins
describe the structure and function of the lysozomes
vesicles bound by a single membrane
F: contain digestive enzymes
describe the structure and function of the chloroplasts
bigger than mitochondria
double membrane
membrane-bound compartments called thylakoids containing chlorophyll stack to form grana
grana are joined by lamellae (thin and flat thylakoid membranes)
F: the site of photosynthesis
describe the structure and function of the vacuole
membrane bound organelle containing cell sap
F: helps isolate unwanted chemicals in the cell + keeps the cell rigid and maintains pressure
describe the structure and function of the cell wall and where is it present
rigid structure that surrounds cells, present in plants, algae and fungi
made of cellulose or chitin
F: supports cells and prevents them from changing shape
how are red blood cells adapted to their function
biconcave and do not contain a nucleus
more space inside the cell so can transport as much oxygen as possible
how are cells that make lots of proteins well adapted
contain many ribosomes (produce proteins)
how do prokaryotic cells differ from eukaryotic cells
cytoplasm that lacks membrane-bound organelles
smaller ribosomes 70s VS eukaryotic cells (80 S)
no nucleus (instead circular DNA)
a cell wall that contains murein (a glycoprotein)
function of a slime capsule
protect bacteria from drying out and from being attacked by immune system cells of the host organism
describe flagellum
long, tail-like structure that rotates, enabling the prokaryote to move
compare prokaryotic cells and eukaryotic cells (6)
eukaryotes are much bigger (100-1000x)
DNA is associated with histones in eukaryotes (forms chromosomes)
DNA is circular with no proteins in prokaryotic cells
70s VS 80s ribosomes
prokaryotes have no membrane bound organelles, eukaryotes have many single + double membraned organelles
prokaryotes replicate by binary fission (no spindle involved) and eukaryotes replicate by mitosis (spindle involved)
prokaryotes have a cell wall made of murein, eukaryotes -cellulose/chitin
