life at the cellular level Flashcards
why are cells so small
larger surface area relative to size
what are prokaryote cells
Bacteria
Lack Nuclear membrane
No Mitochondria
No membrane bound structures
what are Eukaryote cells
Eukaryotic cell Human cells Multicellular animals and plants Nucleus with membrane Membrane bound structures
what are the two types of stem cells
pluripotent - all cell types (embryonic)
multipotent - differentiate into many cells
what are the 4 tissue types that make up organs
epithelial
nervous
muscular
connective (everything else)
what is passive diffusion
Concentration gradient needed
Lipid-soluble molecules pass freely (non-polar)
NON POLAR
what is facilitated diffusion
Concentration gradient needed
Requires carrier molecules
what is endocytosis
when molecules entre the cell via a vesicle
what is exocytosis
when a vesicle exits the cell
what are occluding junctions
tight junctions saling gap between epityilial cells
calcium - blood brain barrier
what are cell-cell anchoring junctions
connects actin filaments bundle in one cell to the
next
what are Gap junctions
create a channel and allow the small passage of water through
what are cell matrix anchoring junctions
anchor cell to basal membrane
what anchors intermediat fillamets in a cell to the extra cellular matrix
hemidesmosome
what are the 4 signalling types
contact dependent - two cells touch endocrine - use the blood stream synaptic - nerves paracrine - one cell releases a local mediator (like endocrine but without the blood)
what other than the nucleus has DNA
mitochondria
what is the rough ER used for
protein modifications
what dose the Golgi do
modifications and transport of proteins
what is the smooth ER used for
to breakdown compounds (e.g. drugs and glycogen) or synthesise some compounds (e.g. lipids)
what are lysosomes used for
to separate harmful enzymes from the rest of the cell
what are microfilaments made up of
what do they do
actin
cell motility in general, changes in cell shape
what is the role of intermediate filaments
largely mechanical, meaning they provide support for the cell
what are the two monomers that make up microtubules
alpha tubulin, beta tubulin
what are the functions of micro tubules
structure of cell
hollow
what are cilia and flagella made of
microtubules
what are cilia
short, usually many present, move with stiff power stroke and flexible recovery stroke
what are flagella
longer, usually one or two present, movement is snakelike
what are micro villi used for
absorption in the gut
what is a central carbon called
chiral
what are the two forms of chiral
L - left handed
D - dextro (right handed)
what is true of most biological redox reactions
two e-’s (and two protons) are gained or lost
Often 2 hydrogen atoms are transferred from one molecule to another in dehydrogenation reactions
what is produced when glucose turns into pyruvate
2NAD+ turn into 2NADH
reduction reaction