Term
| What is a cell? How many different kinds? |
|
Definition
smallest living units in our bodies
-252 |
|
|
Term
| Three main components in a cell? |
|
Definition
1. Plasma membrane- plasmalemma; forms the boundary of each cell
2. Cytoplasm- cytosol+organelles. "little organs" carry out essential functions of cells
3. Nucleus |
|
|
Term
| what is the structure of the plasma membrane model? |
|
Definition
| Fluid Mosaic model; phospholipid bilayer interspersed with protein and cholesterol- some carbohydrate. |
|
|
Term
| What component is the most abundent in the plasma membrane? |
|
Definition
|
|
Term
| types of membrane proteins: |
|
Definition
| integral and peripheral proteins |
|
|
Term
| What is an integral protein? |
|
Definition
| firmly imbedded in or attached to lipid bilayer |
|
|
Term
| Examples of integral proteins: |
|
Definition
| ion channels, carrier proteins, enzymes, receptors. |
|
|
Term
| What is a peripheral protein? |
|
Definition
| attach to membrane surface (most on inner portion of bilayer- most attaching to cytoskeletal filaments). |
|
|
Term
| Whats the function of the plasma membrane? |
|
Definition
barrier between cell and extracellular environment (provides barrier against substances outside the cell).
Forms two body fluid compartments |
|
|
Term
| what two body fluid compartments does teh plasma membrane form? |
|
Definition
intracellular- inside of cell (65% of total body water, TBW)
extracellular fluid outside cell (35% TBW) |
|
|
Term
| What are the type extracellular fluid? |
|
Definition
interstitial fluid-surrounds cells
plasma-fluid portion of blood
other- fluid in joing capsules, eye |
|
|
Term
| What determines which substances enter or leave the cell? How? |
|
Definition
| Plasma Membrane is selectively permeable |
|
|
Term
| How is the membrane selectiveity permeable? |
|
Definition
transport proteins
endocytosis/exocytosis
simple diffusion
osmosis |
|
|
Term
|
Definition
| Phosphate+ 2 long chains of fatty acids orientated in opposite directions (Heads facing out-hydrophillic, tails in-hydrophobic) |
|
|
Term
| How do transport proteins aid in the selective permeable membrane? |
|
Definition
| small lipid insoluble molecules are dependent on integral membrane proteins for movement. |
|
|
Term
| What is the movement of larger molecules called? |
|
Definition
|
|
Term
|
Definition
| lipid soluble molecules pass directly through lipid bilayer of membrane |
|
|
Term
|
Definition
| diffusion of water across a membrane |
|
|
Term
|
Definition
| mechanism by which molecules or particles not able to pass through membrane enter cells. |
|
|
Term
|
Definition
phagocytosis-cell eats large particles
pinocytosis- cell drinks
receptor mediated endocytosis |
|
|
Term
| receptor-mediated endocytosis- |
|
Definition
| receptor-mediated endocytosis- substance binds to ceratin molecules on membrane, invaginates and forms a coated pit, pinches off to become a coated vesicle |
|
|
Term
|
Definition
|
|
Term
|
Definition
| phagocytosis-cell eats large particles |
|
|
Term
|
Definition
| mechanism that moves substances out of the cell |
|
|
Term
| How does exocytosis occur? |
|
Definition
substance is enclosed in a secretory vesicle. The vesicle migrates to the plasma membrane. Proteins from the vesicles (v-snares) bind with membrane proteins (t-snares)
The lipid layers from both membranes bind, and the vesicle releases its contents to the outside of the cell. |
|
|
Term
| What lies internal to the plasma membrane? |
|
Definition
|
|
Term
| what does the cytoplasm consist of? |
|
Definition
| cytosol, organelles, inclusions |
|
|
Term
| What is 50% of the cell volume? |
|
Definition
| cytosol- jelly like fluid in which other cellular elements are suspended. Consists of water ions enzymes |
|
|
Term
| How many categories of organelles are there? what are they? |
|
Definition
| 2- membrane bound and non membrane bound. |
|
|
Term
| What are 5 membrane bound cytoplasmic organelles? |
|
Definition
Endoplasmic reticulum
golgi apparatus
mitochondria
lysosomes
peroxisomes |
|
|
Term
|
Definition
| network w/in the cytoplasm. Flattened envelopes(=cisterns) |
|
|
Term
| Types and functions of different ER? |
|
Definition
rough ER- ribosomes stud the external surfaces- synthesis of proteins to be secreted out of the cell.
Smooth ER- consists of tubules in a branching network. No ribosomes are attached therefore no protein synthesis. Lipid (fat) synthesis, detoxifying enzymes, calcium storage. |
|
|
Term
| What is the golgi apparatus? |
|
Definition
stack of three to ten disck shaped envelopes, receives transport vesicles from ER
- post translational processing of proteins
-sorts products of rough ER and sends them to proper destination |
|
|
Term
| 3 locations golgi apparatus can send products of rough ER? |
|
Definition
| secretory vesicles to plasma membranes, lysosomes, transport vesicles to replace/insert "new" plasma membrane |
|
|
Term
| What is the mitochondria? |
|
Definition
two membranes (inner/outer) and matrix (inner folded into cristae)
Power house of cells- generates metabolic energy=ATP)
enzymes of citric acid cycle (kreb's cycle) in matrix.
electron transport chain on cristae of inner membrane (proteins involved w/ATP production |
|
|
Term
|
Definition
membrane walled sacs constaing acid hydrolase (enzyme)
-digests unwanted substances (both intracellular substances plus substances brought into cells) |
|
|
Term
|
Definition
membrane walled sacs of oxidase enzymes
-catalase (enzyme) neutralizes hydrogen peroxide, protects cell
-break down long chains of fatty acids, amino acids, and toxins
-numberous in the liver and kidneys |
|
|
Term
| What are three Non membrane bound cytoplasmic organelles? |
|
Definition
ribosomes
cytoskeleton
centrioles
Centrosomes |
|
|
Term
|
Definition
| constructed of proteins and ribosomal RNA. It is the site of protein synthesis |
|
|
Term
|
Definition
fixed- attached to ER to synthesis proteins to be secreted by cell
free- loose in cytosol- synthesize non secreted proteins to remain in cell. |
|
|
Term
| what is the cytoskeleton? |
|
Definition
| "cell skeleton" an elaborate network of rod like structures. |
|
|
Term
| functions of the cytoskeleton? |
|
Definition
| cell movement, mechanical support, contraction, suspension/movement of organelles |
|
|
Term
|
Definition
microtubules cylindrical structures made of proteins (tubuin) hollow
microfilaments- contractile protein actin
intermediate filamets- protein fibers |
|
|
Term
|
Definition
| paied cylindrical bodies that consist of 27 short microtubules (9triplets) act in forming cilia mitotic spindle |
|
|
Term
|
Definition
| composed of centrosome matrix (proteins) and centrioles |
|
|
Term
| What are temporary structure, not present in all cell types? What do this consist of? |
|
Definition
cytoplasmic inclusions
-pigments, crystals of protein, food stores (lipid droplets found in liver and glycososomes store sugar as glycogen) |
|
|
Term
|
Definition
| central core or kernel. control center of cell. contains dna. |
|
|
Term
| What does DNA do to the cell? |
|
Definition
|
|
Term
|
Definition
| 5 micro meters in diameter |
|
|
Term
| Whats the nuclear envelope? |
|
Definition
| two parallel membrane seperated by fluid-filled space, contains pores. |
|
|
Term
|
Definition
DNA with histone proteins.
-Condensed chromatin, high coiled strands of DNA.
-exteneded chromatin- contains uncoiled strands of DNA, code can be copied into mRNA |
|
|
Term
| Whats the highest level of organization of chromatin? |
|
Definition
| chromosomes- containing a long molecule of DNA |
|
|
Term
| What is the center or the nucleus? the little nuclueus? |
|
Definition
| nucleolus- contains parts of several chromosomes, site of ribosomes subunit manufacture. |
|
|
