Unit 1 - Cell Physiology Flashcards
how many types of distinct cells are there in the human body?
~200
what are the four broad categories of cells?
1) epithelial cells
2) connective tissue cells
3) nerve cells
4) muscle cells
cells are surrounded by _______ and contain specialized structures called _______.
membranes, organelles
every cell has a nucleus, except:
red blood cells
what is the largest organelle in the cell?
the nucleus
what is the primary function of the nucleus?
storage of DNA in the form of chromatin.
the nucleus is surrounded by a membrane known as the ________, with openings called _________.
nuclear envelope, nuclear pores
nuclear pores facilitate…
- passage of RNA into the cytoplasm
- entrance of proteins that modulate gene expression
what is the nucleolus?
the site of ribosomal RNA synthesis and protein components of ribosomes
what is the smallest cellular organelle?
the ribosome
what is the primary function of the ribosome?
the “protein factory” which translates RNA into protein.
cells that make lots of proteins will have lots of…
ribosomes
do ribosomes have a surrounding membrane?
no
what are the two types of ribosomes?
free ribosomes and membrane-bound ribosomes
which organelle is continuous with the rough ER and the nuclear envelope?
smooth ER
what is the primary function of the smooth ER?
fatty acid synthesis, calcium storage and release, etc.
what is the primary function of the rough ER?
site of protein synthesis
proteins synthesized in the lumen are…
distributed to other organelles or secreted
the orgenelles that is comprised of a series of membranous sacs called cisternae is the…
golgi apparatus
what is the function of the golgi apparatus?
modifies and sorts proteins arriving from the ER, and distributing them to other organelles or to the membrane for secretion.
the small membrane-bound vesicles spread throughout the cytoplasm are…
endosomes
what is the function of the endosomes?
sorting vesicular traffic in the cell
what is the function of the lysosomes?
breakdown:
- damaged/worn out organelles
- engulfed bacteria
- engulfed debris of dead cells
which organelle has an acidic environment and contains digestive enzymes?
lysosomes
what is the function of peroxisomes?
breakdown:
- fatty acids
- detoxification of alcohol
what is the function of the mitochondria? (i swear to god if you say the powerhouse of the cell)
transfers energy in the form of ATP in a process called cellular respiration.
what is the function of the cytoskeleton?
provides structural support, facilitates change in cell shape, an produces cell movement.
what are the three classes of the cytoskeleton?
1) actin filaments
2) intermediate filaments
3) microtubules
which class of the cytoskeleton is made of hollow tubes, and is formed of tubulin subunits?
microtubules
which class of the cytoskeleton is made up of twisted strands of proteins like keratin, desmin, and laminin?
intermediate filaments
which class of the cytoskeleton contains G-actin subunits which form a polymer of two twisting chains, forming F-actin?
actin filaments
what is ribosomopathy?
multiple causes of abnormal ribosomal biogenesis resulting in human disease
true or false: ER stress is not secondary to other diseases.
false. it is secondary to things like cancer, neurodegeneration, and metabolic disease.
what is ER stress?
altered ER funtion results in accumulation of unfolded/misfolded protiens, this may cause apoptosis.
is mitochondrial mytopathy primary or secondary?
haha pranked it can be both
what is a lysosomal storage disorder?
one where toxic material build up in the lysosome.
what are the three key components of the fluid mosaic model?
1) phospholipid bilayer
2) cholesterol
3) proteins
what does it mean for phospholipids to be amphipathic?
they have a hydrophilic head and a hydrophobic tail.
what is the main function of cholesterol in the cell membrane?
to maintain membrane fluidity.
what are the two classes of membrane proteins?
1) integral membrane proteins
2) peripheral membrane proteins
which membrane proteins are amphipathic and are embedded in the membrane/membrane spanning?
integral membrane proteins
which membrane proteins are not amphipathic and lie on the membrane surface?
peripheral membrane proteins
what are the four main functions of the membrane proteins?
1) link adjacent cells together
2) regulate passage of substances into and out of the cell
3) detect chemical messengers arriving at the cell surface
4) anchor cells to extracellular matrix
cell membranes can join together to form…
junctions
what are the three major types of cell junctions?
1) desmosomes
2) tight junctions
3) gap junctions
what are desmosomes?
stong links that give high structural integrity.
what are tight junctions?
forms tight barriers so things can’t get through the cells.
what are gap junctions?
pores between cells, allowing passage of ions and small molecules.
what are the four mechanisms that molecules use to cross membranes?
1) diffusion
2) protein-mediated transport
3) vesicular transport
4) epithelial transport