cell structure and function Flashcards
what are elements common to all living cells
plasma membrane
cytoplasm
chromosomes
ribosomes
cytoskeleton
what are all cells surrounded by
the plasma membrane
what is the plasma membrane
a bilayer made of phospholipid molecules with embedded protein molecules
what kind of membrane is the plasma membrane
semi-permeable - control the flow of substances into and out of the cell
what is the lipid bilayer
a hydrophobic barrier to water soluble substances
what is cytosol
aqueous portion of the cytoplasm in an intact cells, containing water, dissolved ions and various organic molecules
what are prokaryotic cells
bacteria and archea
what are eukaryotic cells
animals
plants
fungi
protists
where is DNA stored in prokaryotic cells
nuceloid
what do prokaryotic cells lack
membrane bound organelles
what are 3 common shapes in prokaryotic cells
spherical, rodlike, spiral
what is the shape of DNA in prokaryotic cells
single, circular molecule
when the polysaccharides surrounding the plasma membrane are attached its called what
a capsule
what do the molecular systems in the plasma membrane do
metabolize food molecules into chemical energy of ATP
t or f prokaryotic cytoskeletons maintain cell shape and function in cell division
true
how do prokaryotic cells move
long flagella
what does the bacterial flagellum do
rotates in a socket and pushes the cell through a liquid medium
what do the pili do
like velcro, attatch to the surface of other cells
what are plasmids
circles of DNA that replicate independently of the chromosomes
what is the purpose of organelles
energy metabolism, molecular synthesis, store and transport
where are eukaryotic ribosomes
free in cytosol or attached to membranes
what does the end-membrane system do
divides the cytoplasm into functional and structural compartments
where does cellular respiration occur
mitochondria
what are in animal cells but not plant cells
lysosomes, centrioles and flagella
what are in plant cells but not animal cells
chloroplasts, central vacuole, cell wall
what is the nuclear envelope
made up of 2 lipid bilayer membranes
in eukaryotic cells it surrounds the nucleus
what is the nuclear pore
protein-lined channel in the nuclear envelope that regulates the transportation of molecules between the nucleus and cytoplasm
what does the nucleus do
assembles ribosomes
what is chromatin
complex of DNA and proteins that form chromosomes within the nucleus of eukaryotic cells
what are ribosomes
particles made up of ribosomal RNA and proteins
where do ribosomes carry out protein synthesis
cytosol and outside the ER
what are the components of the end-membrane system (6)
nuclear envelope
endoplasmic reticulum
Golgi apparatus
lysosomes
vacuoles
plasma membrane
what is the function of the rough ER
involved with modifications and folding of proteins which are distributed by transport vesicles
membrane factory for the cell
what does the smooth ER do
synthesize lipids
regulates CHO metabolism
stores calcium
detoxifies toxins and drugs
what does the Golgi apparatus consist of
flattened membranous sacs called cisternae
what is the function of the Golgi apparatus
modifies products of the ER
manufactures certain macromolecules
sorts and packages materials into transport vesicles
what is the Golgi apparatus known as
the shipping and receiving centre.
what are lysosomes known as in the cell
digestive compartments
what does a lysosome consist of
membranous sac of hydrolytic enzymes
what do lysosomes do
hydrolyze proteins, fats, polysaccharides and nucleic acid
what do lysosomes use to recycle organelles
enzymes; process called autophagy
what is phagocytosis
cellular process by which a cell uses the plasma membrane and engulfs a large particle
what does autophagy do
conserved deflation of the cell that removes unnecessary or dysfunctional components
allows deflation and recycling of cellular components
what do vesicles do
form by exocytosis, uptake endocytosis and the transport of materials within the cell membrane
how are food vacuoles formed
phagocytosis
what do contractile vacuoles do
pump excess water out of the cell
what do central vacuoles do
hold organic compounds and water
another way to remember end-membrane system
organization of cell
what are the mitochondria’s
sites of cellular respiration
what are chloroplasts
only found in plants and animals
site of photosynthesis
t or f mitochondria and chloroplasts are not part of the end-membrane system
true
what are peroxisomes
oxidative organelles
what is the structure of the mitochondria
outer membrane and inner membrane folded into cristae
what do the two inner membranes create in the mitochondria
inter membrane space and mitochondrial matrix
what does cristae do
area for enzymes to sysnthesize ATP
t or f chloroplasts are part of a family of organelles called plastids
true
what do chloroplasts contain
chlorophyll and enzymes that function in photosynthesis
what do peroxisomes do
produce hydrogen peroxide and convert it to water
what are microtubules
the thickest of 3 components of the cell
what are microfilaments (actin filaments)
the thinest components
what are intermediate filaments
filers
what does the cytoskeleton do
interacts with motor proteins to proud motility
helps regulate biochemical activities
vesicles can travel along monorails provided by cytoskeleton
what is the function of microtubules
shaping cell
guiding movement of organelles
separating chromosomes during cell division
making internal structure of cilia and flagella
what are cilia and flagella
motile cellular appendages found in mostly animals
aid in cell movement
what do microfilaments do
actin works with myosin to regulate muscle movements, cell division
they form a 3D network just inside the plasma membrane to help support the cells shape
what are plant cell walls made up of
cellulose fibres embedded in other polysaccharides and proteins
what is plasmadosmata
channels between adjacent plant cells
what is the ECM made of
glycoproteins and macromolecules
what is the function of the ECM
support
adhesion
movement
regulation
what are tight junctions
membranes of neighbouring cells that are pressed together, preventing leakage of extracellular fluid
what are desmosomes
the anchoring junction
fasten cells together into strong sheets
what are gap junctions
communicating junctions
provide cytoplasmic channels
