Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Anatomy > Chapter 3 cells > Flashcards

Chapter 3 cells Flashcards

1
Q

cell theory

A

The cell is the smallest structural and functional living unit
all cells come from existing cells
Organismal functions depend on individual and collective cell functions
Biochemical activities of cells are dictated by their specific subcellular structures
Continuity of life has a cellular basis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

membrane lipids

A

75% phospholipids (lipid bilayer)
5% glycolipids
20% cholesterol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

glycolipids

A

for cell recognition

Lipids with polar sugar groups on outer membrane surface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

cholesterol

A

Increases membrane stability and fluidity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Integral proteins

A 
Firmly inserted into the membrane (most are transmembrane)
Functions: 
Transport proteins (channels and carriers), enzymes, or receptors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

tight junctions

A

Prevent fluids and most molecules from moving between cells
Impermeable junctions prevent molecules
from passing through the intercellular space.
Examples: kidneys, , bile duct

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Desmosomes

A

Rivets” or “spot-welds” that anchor cells together

structure support, keep cell from pulling apart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

gap junctions

A

Transmembrane proteins form pores that allow small molecules to pass from cell to cell
Communicating junctions allow ions and small mole-cules to pass
For electrical synapses (not in skeletal muscle)
For movement of ions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Passive processes

A

No cellular energy (ATP) required
Substance moves down its concentration gradient
diffusion, facilitated diffusion, osmosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

active processes

A

Energy (ATP) required

Occurs only in living cell membranes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What determines whether or not a substance can passively permeate a membrane

A

Lipid solubility of substance
( easier to remember: If water soluble or polar, simple diffusion won’t work)
Channels of appropriate size
Carrier proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

facilitated diffusion

A 
Certain lipophobic molecules (e.g., glucose, amino acids, and ions) use carrier proteins or channel proteins, both of which:
Exhibit specificity (selectivity)
Are saturable; rate is determined by number of carriers or channels
Can be regulated in terms of activity and quantity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Facilitated Diffusion Using Carrier Proteins

A

Transmembrane integral proteins transport specific polar molecules (e.g., sugars and amino acids)
Binding of substrate causes shape change in carrier

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Facilitated Diffusion Using Channel Proteins

A

Aqueous channels formed by transmembrane proteins selectively transport ions or water
Two types:
Leakage channels
Always open
Gated channels
Controlled by chemical or electrical signals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

osmosis

A

Movement of solvent (water) across a selectively permeable membrane
Water diffuses through plasma membranes:
Through the lipid bilayer
Through water channels called aquaporins (AQPs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Membrane permeable to both solutes and water

A

Solute and water molecules move down their concentration gradients
in opposite directions. Fluid volume remains the same in both compartments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Membrane permeable to water, impermeable to solutes

A

Solute molecules are prevented from moving but water moves by osmosis.
Volume increases in the compartment with the higher osmolarity.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

tonicity

A

The ability of a solution to cause a cell to shrink or swell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

isotonic

A

A solution with the same solute concentration as that of the cytosol
remains same

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

hypertonic

A

A solution having greater solute concentration than that of the cell, cell loses water and shrinks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

hypotonic

A

A solution having lesser solute concentration than that of the cell, cell swells and can lysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Two types of active processes

A

Active transport
Vesicular transport
Both use ATP to move solutes across a living plasma membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Active Transport

A

Requires carrier proteins (solute pumps)

Moves solutes against a concentration gradient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Primary Active Transport

A

Energy from hydrolysis of ATP causes shape change in transport protein so that bound solutes (ions) are “pumped” across the membrane
na k pump

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Secondary Active Transport
Depends on an ion gradient created by primary active transport Energy stored in ionic gradients is used indirectly to drive transport of other solutes
26
Cotransport
Cotransport—always transports more than one substance at a time
27
Symport system
Two substances transported in same direction
28
Antiport system
Two substances transported in opposite directions
29
Vesicular Transport
Transport of large particles, macromolecules, and fluids across plasma membranes Requires cellular energy (e.g., ATP)
30
Exocytosis
Exocytosis—transport out of cell
31
endocytosis
transport into cell
32
Receptor mediated vesicular
phagocytosis and pinocytosis | selective
33
Transcytosis
Transcytosis—transport into, across, and then out of cell
34
Substance (vesicular) trafficking
Substance (vesicular) trafficking—transport from one area or organelle in cell to another
35
Phagocytosis
Phagocytosis—pseudopods engulf solids and bring them into cell’s interior Macrophages and some white blood cells
36
pinocytosis
Fluid-phase endocytosis (pinocytosis)—plasma membrane infolds, bringing extracellular fluid and solutes into interior of the cell Nutrient absorption in the small intestine
37
exocytosis
``` Hormone secretion Neurotransmitter release Mucus secretion Ejection of wastes vesicle binds to membrane, ruptures, spills contents out ```
38
membrane potential
Separation of oppositely charged particles (ions) across a membrane creates a membrane potential (potential energy measured as voltage)
39
resting membrane potential
Voltage measured in resting state in all cells Results from diffusion and active transport of ions (mainly K+) and na
40
Generation and Maintenance of RMP
The Na+ -K+ pump continuously ejects Na+ from cell and carries K+ back in Some K+ continually diffuses down its concentration gradient out of cell through K+ leakage channels Membrane interior becomes negative (relative to exterior) because of large anions trapped inside cell
41
Roles of Membrane Receptors
contact signalling chemical signaling g protein linked recptors
42
contact signaling
Contact signaling—touching and recognition of cells; e.g., in normal development and immunity
43
chemical signaling
Chemical signaling—interaction between receptors and ligands (neurotransmitters, hormones and paracrines) to alter activity of cell proteins (e.g., enzymes or chemically gated ion channels)
44
g protein linked receptors
ligand binding activates a G protein, affecting an ion channel or enzyme or causing the release of an internal second messenger, such as cyclic AMP (cascade reactions)
45
cell cycle
Defines changes from formation of the cell until it reproduces Includes: Interphase Cell division (mitotic phase)
46
interphase
Period from cell formation to cell division Nuclear material called chromatin Four subphases: G1 (gap 1)—enzymes for dna rep G0—gap phase in cells that permanently cease dividing (QUIESCENT) S (synthetic)—DNA replication G2 (gap 2)—preparation for division (enzymes) spindle fiber
47
mitosis
growth repair, everywhere
48
meiosis
sexual reproduction, making gametes, reproductive organs
49
cell division
mitosis four stages, | prophase, metaphase, anaphase, telophase
50
dna replication
helicase unwinds dna DNA polymerase only works in one direction Continuous leading strand is synthesized Discontinuous lagging strand is synthesized in segments DNA ligase splices together short segments of discontinuous strand
51
control of cell division go signals
Critical volume of cell when area of membrane is inadequate for exchange Chemicals (e.g., growth factors, hormones, cyclins, and cyclin-dependent kinases (Cdks))
52
control of cell division stop signals
Contact inhibition | Growth-inhibiting factors produced by repressor genes
53
Protein Synthesis
DNA is the master blueprint for protein synthesis Gene: Segment of DNA with blueprint for one polypeptide Triplets of nucleotide bases form genetic library Each triplet specifies coding for an amino acid
54
Gene:
Segment of DNA with blueprint for one polypeptide
55
Messenger RNA (mRNA)
Carries instructions for building a polypeptide, from gene in DNA to ribosomes in cytoplasm carry codon
56
Transfer RNAs (tRNAs)
Bind to amino acids and pair with bases of codons of mRNA at ribosome to begin process of protein synthesis anticodons
57
Transcription
Transfers DNA gene base sequence to a complementary base sequence of an mRNA
58
transcription three steps
initiation, elongation, termination
59
initiation
With the help of transcription factors, RNA polymerase binds to the promoter, pries apart the two DNA strands, and initiates mRNA synthesis at the start point on the template strand
60
elongation
As the RNA polymerase moves along the template strand, elongating the mRNA transcript one base at a time, it unwinds the DNA double helix before it and rewinds the double helix behind it.
61
termination
mRNA synthesis ends when the termination signal is reached. RNA polymerase and the completed mRNA transcript are released.
62
Translation
Converts base sequence of nucleic acids into the amino acid sequence of proteins
63
codon
Each three-base sequence on DNA is represented by a codon | Codon—complementary three-base sequence on mRNA
64
translation process
mRNA attaches to a small ribosomal subunit that moves along the mRNA to the start codon Large ribosomal unit attaches, forming a functional ribosome Anticodon of a tRNA binds to its complementary codon and adds its amino acid to the forming protein chain New amino acids are added by other tRNAs as ribosome moves along rRNA, until stop codon is reached
65
Ubiquitin
(regulatory protein in all tissues) tags damaged or unneeded soluble proteins in cytosol; they are digested by enzymes of proteasomes
66
Active transport process
Nucleus, to rough ER, vesicle, golgi, vesicle, plasma membrane for exocytosis
67
Transcription factors
Enzymes and proteins Loosen histones (help package dna into chromosome) Binds to promoter Mediates bonding of RNA polymerase to promoter
68
Transcription rna polymerase
Unzips and copies dna by itself, stops at termination codon Only copy one strand with right gene Only unwound in rna polymerase
69
Translation process
Mrna attaches to ribosome Anticodon attaches to codon Adds amino acids to forming protein Stops at stop codon
70
Homeostasis process order
``` Stimulus Receptor Afferent pathway Control center Efferent pathway Effector Return to balance ```
71
Glycoproteins
Recieve signal
72
Glycolipid
Cell recognition

Anatomy (29 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions