The Anatomy and Physiology of The Cell - AnaPhy Lecture Flashcards
1
Q
- Acts as a boundary
- Controls what enters and leaves cell
- Regulates chemical composition
- Maintains homeostasis
A
Plasma Membrane
2
Q
What is the structure of a Plasma Membrane?
A
Fluid Mosaic Model
3
Q
Plasma membrane has a
A
Phospholipid bilayer with proteins partially or fully
imbedded
4
Q
- Acts as a boundary
- Controls what enters and leaves cell
- Regulates chemical composition
- Maintains homeostasis
A
Plasma membrane
5
Q
the plasma membrane has the consistency of olive oil at body temperature, due to unsaturated phospholipids.
A
Fluid
6
Q
membrane proteins form a collage that differs on either side of the membrane and from cell to cell (greater than 50 types of proteins), proteins span the membrane with hydrophilic portions facing out and hydrophobic portions facing in.
A
Mosaic
7
Q
Substance Permeability Across Membrane
Few molecules move freely:
A
Water, Carbon dioxide, Ammonia, Oxygen
8
Q
embedded in lipid bilayer
A
Transport Proteins
9
Q
channel for lipid insoluble molecules and ions to pass freely through
A
Channel Proteins
10
Q
bind to a substance and carry it across membrane, change shape in process
A
Carrier Proteins
11
Q
Types of Passive Transport
A
- Diffusion
- Osmosis
- Facilitated diffusion
12
Q
- molecules move to equalize concentration
A
Diffusion
13
Q
- Special form of diffusion
- Fluid flows from lower solute concentration to higher solute concentration
- Often involves movement of water: Into cell/Out of cell
A
Osmosis
14
Q
solvent + solute =
A
solution
15
Q
– Solutes in cell more than outside
– Outside solvent will flow into cell
A
Hypotonic
16
Q
– Solutes equal inside & out of cell
A
Isotonic
17
Q
– Solutes greater outside cell
– Fluid will flow out of cell
A
Hypertonic
18
Q
- Channels (are specific) help molecule or ions enter or leave the cell
- Channels usually are transport proteins (Aquaporins facilitate the movement of water)
- No energy is used
A
Facilitated Diffusion
19
Q
How does facilitated diffusion work?
A
- Protein binds with molecule
- Shape of protein changes
- Molecule moves across membrane
20
Q
- movement of water and solute molecules across the cell membrane due to hydrostatic pressure generated by the cardiovascular system.
- Depending on the size of the membrane pores, only solutes of a certain size may pass through it.
A
Filtration
21
Q
- Molecular movement
- Requires energy (against gradient)
A
Active transport
22
Q
example of active transport
A
sodium-potassium pump
23
Q
Movement: To the ICF
Vesicles: Large membrane bound vesicle
Mechanism: phagosome pinches off from the cell membrane
A
phagocytosis
24
Q
engulfs a bacterium or other particles
A
phagocytosis
25
To move large molecules or particles into cells
endocytosis
26
Movement: To the ICF
Vesicles: Smaller vesicles
Mechanism: membrane surface indents, could be nonselective or receptor mediated
endocytosis
27
export large lipophobic molecules, (proteins), get rid of wastes left in lysosomes, insert proteins into the cell membrane
exocytosis
28
Movement: To the ECF
Vesicles: Intracellular vesicles
Mechanism: Rabs, help vesicles dock onto the membrane, & SNAREs, which facilitate membrane fusion
exocytosis
29
Movement of large material
– Particles
– Organisms
– Large molecules
Movement is into cells
endocytosis
30
Types of endocytosis
* bulk-phase (nonspecific)
* receptor-mediated (specific)
31
Process of Endocytosis
1. Plasma membrane surrounds material
2. Edges of membrane meet
3. Membranes fuse to form vesicle
32
- Reverse of endocytosis
- Cell discharges material
exocytosis
33
Process of Exocytosis
1. Vesicle moves to cell surface
2. Membrane of vesicle fuses
3. Materials expelled
34
Components of Cytoplasm
– Interconnected filaments & fibers
– Fluid = cytosol
– Organelles (not nucleus)
– Storage substances
35
Cytoskeleton are made of 3 fiber types
microfilaments, microtubules, intermediate filaments
36
strands made of spherical protein subunits called actins
microfilaments
37
hollow tubes of spherical protein subunits called tubulins
microtubules
38
tough, insoluble protein fibers constructed like woven ropes composed of tetrameter (4) fibrils
intermediate filaments
39
– mechanical support
– anchor organelles
– help move substances
Cytoskeleton
40
– Short
– Used to move substances outside human cells
cilia
41
– Whip-like extensions
– Found on sperm cells
Flagella
42
- Increase surface area in small intestine for absorption of nutrients
- made up of actin filaments
Microvilli
43
- a microtubule organizing center made up of pairs of centrioles
centrosome
44
- small, barrel-shaped organelles
centrioles
45
- Control center of cell
- Double membrane
nucleus
46
- Separates nucleus from rest of cell
- Double membrane
- Has pores
nuclear membrane
47
- Hereditary material
DNA
48
- Most cells have 2 or more
- Directs synthesis of rRNA
- Forms ribosomes
Nucleolus
49
- Dense particles consisting of two subunits, each
- composed of ribosomal RNA and protein.
- Free or attached to rough endoplasmic reticulum.
- the sites of protein of synthesis.
Ribosomes
50
- Helps move substances within cells
- Network of interconnected membranes
Endoplasmic Reticulum
51
Two types of ER
– Rough endoplasmic reticulum
– Smooth endoplasmic reticulum
52
- With ribosomes attached to surface
- Manufacture proteins
Rough Endoplasmic Reticulum
53
- No attached ribosomes
- Has enzymes that help build molecules: Carbohydrates and Lipids
– Smooth endoplasmic reticulum
54
- A stack of flattened membranes and associated vesicles close to the nucleus.
- Packages, modifies, and segregates proteins for secretion from the cell, inclusion in lysosomes, and incorporation into the plasma membrane
Golgi Apparatus
55
- Contain digestive enzymes
* Aid in cell renewal
* Break down old cell parts
* Digests invaders
* Contains acid hydrolases
Lysosomes
56
release energy
mitochondria
57
store energy
chloroplasts
58
- Have their own DNA
- Rodlike, double-membrane structures; inner membrane folded into projections called cristae.
- Break down fuel molecules
mitochondria
59
- cells in various regions of the embryo are exposed to different chemical signals that channel them into specific pathways of development
Cell Differentiation
60
- attributes aging to little chemical insults and formation of free radicals, both of which have cumulative effects.
wear-and-tear theory
61
- Most free radicals are produced in the mitochondria.
mitochondrial theory of aging
62
According to this theory, cell damage results from (1) autoimmune responses, which means the immune system turns against one’s own tissues, and (2) a progressive weakening of the immune response, so that the body is less able to get rid of cell-damaging pathogens.
cell aging due to progressive disorders in the immune system
63
which means the immune system turns against one’s own tissues
autoimmune responses
64
so that the body is less able to get rid of cell-damaging pathogens.
a progressive weakening of the immune response
65
Cessation of mitosis and cell aging are “programmed into our genes.”
One interesting notion here is that a telomere clock determines the number of times a cell can divide.
genetic theory
66
an enzyme that lengthens the previously shortened telomeres
telomerase
67
telomerase is pegged as the
immortality enzyme
68
is found in germ line cells (cells that give rise to sperm and ova), but it is absent or barely detectable in other adult cell types.
telomerase
69
- programmed cell death
- particularly common in the developing nervous system.
- “Carving out” fingers and toes from their embryonic webbed precursors
- eliminates cells that are stressed, no longer needed, injured, or aged
apoptosis
