Cell And Cell Transport Flashcards
What are the roles of the cell membrane?
A. Maintain sufficient amount of molecules within the cell.
B. Regulated uptake and release of ions.
C. Regulate bidirectional transmission of signals
D. Compartmentalization
AOTA
There is both fluid outside and inside the cell? T/F
T
Intracellular and interstitial fluid
It composes of 15% of body weight.
Interstitial fluid
It composes of 40% body weight
Intracellular fluid
How much does blood plasma comprise in terms of body weight
5%
Where is the greatest amount of fluid found in the body?
Intracellular cell
Extracellular fluid is made up of 2 parts. Enumerate.
Interstitial fluid
Blood plasma
Extracellular fluid is _____ of body weight
20%
Mores:
Water comes inside the body via stomach and intestines.
Water comes out of the body via lungs.
We loose fluid by sweat and kidneys.
We loose fluid by stool.
T - eat or drink
T
T - sweat
F - no significant fluid lose as intestines are good in reabsorption
Ion that is mostly found in intracellular?
POTASSIUM
remember: POTASSIUM IN
SODIUM OUT
Which has higher amount of Na+, outside or inside the cell?
Out
Other molecules that intracellular fluid contain in large amount?
K+
Proteins
Misc. Protreins
Bicarbonate has higher amount inside or outside the cell?
Out
Mass ratio of protein to lipid of CM
1:1
Structure of cell membrane. Symmetrical or asymmetrical?
Assy.
Because proteins have unique differentiations
CM thickness
7.5 to 10nm
Main components of CM
Phospholipid
Cholesterol
Protein
Carbohydrates chain
Composed of 4 fused carbon rings and located in the core of the membrane.
Cholesterol
Carbohydrates can only be seen in the surface of the membrane. T/F
NOT SURE DITO MEDYO MISLEADING UNG TANONG
T
Carbs are only attached to lipids and protein along the extracellular side. T/F
T
Forming glycoproteins and glycolipids
Phospholipids
Main fabric of membrane
Integral proteins located
May or May not be seen through and through the membrane. It is embedded.
Peripheral proteins location
Found in the outer surface or embedded in the hydrophilic head of the membrane. NOT in its hydrophobic core.
Cell membrane comprises of ____ amount of lipids.
40%
Types of lipids found in the cell membrane.
Phospholipids
Cholesterol
Other lipids
% of phospholipids in the CM
25%
% of cholesterol in CM
13%
% of other lipids in CM
4%
Role of cholesterol in CM
Maintains membrane permeability and fluidity.
Stabilize normal body tempt
2 parts of phospholipid layer of CM
Inner and outer leaflet
Enumerate the phospholipid found in the inner and outer leaflet.
Outer
- phosphatidylcholine
- sphingomyelin
Inner
- phosphotidylethanolamine
- phosphotidylserine
- phosphotidylinositol
Does CM contain TG?
None
Only ____________ substances can cross the CM as they can dissolve in the hydrophobic layer.
Lipid - soluble
Lipid soluble molecules
02, CO2, steroid hormones
Cholesterol can be found in both leaftlets. T/F
T
Integral proteins are anchored to the membrane by what forces?
Van der waals forces & hydrophobic interactions
Peripheral proteins
Loosely attached proteins in the cell membrane
Integral proteins : hydrophobic bonds & van der waals/electrostatic forces
Peripheral proteins : _______
Covalent bond
Major functions if membrane proteins
Receptors
Enzymes
Channels
Gated channels
Cell - identity marker
Cell - adhesion molecule
Binds to chemical messengers such as hormones and neurotransmitters.
Receptors
Enzyme
Breakdown the chemical messengers to stop its effect
A protein that allows entry of solutes anytime or constantly into the cell.
Channel (open channel)
Gated channel
Only allow certain solutes to enter the cell
Cell identity marker
Glycoprotein that identify whether the cell trying to enter is foreign or not.
Protein that binds one cell to another
Cell adhesion molecule (CAMP)
Enumerate the 3 Major classes of plasma membrane transporters. Give example.
Pores - water channel (AQ1)
Channels - shaker K+ channels
Carriers - glucose transporter (GLUT1)
A major plasma membrane transporters that is continously open
Pores
Major class of plasma membrane transporters that is intermittently open
Channels
Major class of plasma membrane transporters that is NEVER open due to cycles of conformational changes.
Carrier
The fastest of all the plasma transporters
Pores
The slowest PM transporter
Carriers - they carry heavy molecules
State the PM transporters according to fastest to slowest.
Pores > channels > carriers
What are the functions of carbohydrates located at the surface of the CM?
Physical barrier - repelling negatively charged objects on the surface
Cell adhesion - glycocalyx of some cell bind to other glycocalyx of another.
Cell signaling - hormones bind to receptor sites such as insulin.
Cell recognition - aid in immune response to identify foreign bodies.
Cluster of lipids and proteins that have diff stru9cture, composition, and function from the rest of the cells in the membrane.
Membrane microdomains
These are unique proteins and lipids that regulate signaling pathways by providing a concentrated enriched microenvironment for lipids and proteins.
Membrane micrdomain
2 examples of membrane microdomain
Rafts
Caveolae
Differentiate raft from caveolae
Rafts- cholesterol and saturated lipids. Highly structured. Distinct from surrounding disordered instantiated lipids.
Caveolae - uncoated cell surface invagination. Main role is for endocytosis.
Protein found in caveolae
Caveolin
B =1
Molecule dissolves equally easy in water and lipids
B > 1
Molecule is MORE easily dissolved in lipid bilayer
B < 1
Molecule dissolves LESS easily in lipid bilayer
Movement of water between the ICF (intracellular fluid) and ECF
(extracellular fluid) compartments, across cell membranes, occurs
through _________ _
Aquaporins
The driving force for this water movement between ICF and ECF.
osmotic pressure difference 📖
Principal lipid components plasma membrane
Phospholipids and cholesterol
Collectively, these glycolipids and glycoproteins form the
Glycocalyx
Tucked between the hydrophobic tails of the
membrane phospholipids
Cholesterol
(plays an important role in signal transduction
Phosphotydylinositol
One important function of these is to segregate signaling molecules
Rafts
How to maximize the amount of particles over time
○ Less thick wall
○ Small MW molecules – faster diffusion rate (Graham’s Law)
○ Increased P1 (pressure at position 1)
○ Increased (surface) area
Talks about the amount of particles moving over time
Fick’s law
Henry’s Law
increased pressure (P1), increased solubility
Graham’s Law
lower 𝑀𝑊, increased diffusion rate
“Net Rate” of particles moving through an area
V/A = Flux
Gradient
Change in pressure (“particles in a volume”) over a distance
diffusion coefficient considers the thermal energy of the molecule,
its size, and the viscosity of the medium through which diffusion is
taking place. T/F
T
the more lipid soluble the molecule is, meaning
the partition coefficient is greater than 1, the larger partition coefficient,
and also the diffusion coefficient. T/F
T
Aka Electrochemical Potential Difference
Electrochemical gradient
2 components of electrochemical gradient
Chemical potential difference
Electrical potential difference
energy or the driving force that is caused changes or differences in the concentration gradient for X across the membrane
Chemical potential difference
energy associated with moving charged molecules
Electrical potential difference
What protein coats the pits of the endocytic vesicles for
receptor-mediated endocytosis:
a) Clathrin
b) Dynamin
c) Caveolin
d) Actin
A
What is a true statement regarding cell membrane phospholipids?
a) Their polar headed are on the outer surfaces
b) Their mass ratio with proteins is 2:1
c) They asymmetrically arranged
d) They comprise 60% of membrane components
A
Which cell transport always allows free flow of molecules across the
cell membrane?
a) Facilitated diffusion through carrier
b) Diffusion through protein channels
c) Diffusion through the lipid bilayer
d) Secondary co-transport through carriers
C
The perinuclear space connects to the
a) Smooth endoplasmic reticulum
b) Cell membrane
c) Golgi apparatus
d) Rough endoplasmic reticulum
D
The predominant negatively charged molecule in the extracellular fluid
is:
a) Sodium
b) Protein (negatively charged but not predominant)
c) Bicarbonate (negatively charged but not predominant)
d) Chloride
D
Thin filaments:
a) Compose the centrioles and mitotic spindles
b) Gives strength and support to microtubules
c) Are desmin filaments in muscle cells
d) Provide elastic support for the cell membrane
D
facilitated by membranes so that different organelles may perform different functions
Compartmentalization
● The eukaryotic cell is divided into two main compartments:
Nucleus & cytoplams
Most important organelle of the cell
Nucleus
A highly specialized organelle that serves as the information processing
and administrative center of the cell
Nucleus
All human cells have a nucleus, except mature human red blood cells and
cells within the lens of the eyes. T/F
T
semifluid matrix found inside the nucleus containing the chromatin
Nucleoplasm
tightly wrapped DNA-protein chain around DNA-binding proteins (i.e. histones
Nucleosome
The DNA is combined with proteins and organized into a precise,
compact structure, a dense string-like fiber called _________.
Chromatin
6 feet of DNA, divided into 46 individual molecules
Chromosomes
Membraneless organelle within the nucleus that has the main function
of manufacturing ribosomes
Nucleolus
→Site of ribosomal RNA transcription and assembly of ribosomal
subunits.
Nucleolus
How is mRNA transported outside the nucleolus?
Nuclear pores
Double-layered membrane that encloses the contents of the nucleus
during most of the cell’s life cycle
Nuclear membrane
The space between the layers of the nuclear envelope is called _____
Perinuclear space
perinuclear space of the nuclear envelope appears to connect with the rough endoplasmic reticulum. T/F
T
Tiny holes that regulate the passage of molecules between the nucleus and cytoplasm
Nuclear pores
meshwork that provides mechanical strength to the nucleus
Nuclear lamina
Inner lining of the nuclear envelope is coated in a protein called _____
Nuclear lamina
Cytoplasmic proteins and signaling molecules for the nucleus require a
nuclear-localization sequence to gain entry. T/ F
T
Main export of the nucleus used for protein synthesis.
RNA transcripts
● Product of the nucleolus inside the nucleus. 💬
● Micro-machine for making proteins
Ribosomes
Type of ribosome that is important in translation of mRNA into cytosolic proteins
Free ribosomes
Type of ribosome that gives the granular appearance of the rough
endoplasmic reticulum.
Bound ribosome
After a ribosome performes it’s task it disintegrate. T/F
T
Functions of ribosomes
Translate information
Link amino acid sequences
Export polypeptides
Group of membranes and organelles in eukaryotic cells that work together
to modify, package, and transport lipids and proteins
Endomembrane system
Network of tubular structures in ER is called ______
Cisternae
Site of protein synthesis
Rough endoplasmic reticulum
Centrally located near the nucleus
RER
Er that is near the cell periphery
Smooth RER
Main function is lipid synthesis and calcium storage
SER
Other functions of SER
- Mobilization of glucose
from glycogen - Calcium storage
- Drug detoxification
- Synthesis of lipids
Four or more stacked layers of thin, flat, enclosed vesicles
Golgi apparatus
Function is to take in secretory vesicles in the cis region and pinches off in the trans region
Golgi apparatus
Where is lysosomes created?
Golgi app
Function is to digest materials. Extremely acidic environment and contains 40 different hydrolase (digestive enzymes).
Lysosomes
Specific vesicles that bring materials to the lysosomes.
Endosomes
How are materials brought in the golgi. Process.
Microautophagy & macroautophagy
Specific to protein degradation
Proteases
serves as a degradation signal for numerous target proteins
Ubequitin
antitumor activity (bortezomib)
Inhibitor of proteasome
Function is to Detoxification of substances, and catabolism of long chain fatty acids. Contains oxidative enzymes
Peroxisomes
Site of β oxidation of fatty acid molecules and catabolism of D-amino
acids, polyamines and bile acids
Peroxisomes
Site of oxygen-dependent ATP production: oxidative phosphorylation
Mitochondria
It maintains and replicates its own genome: makes up the mitochondrial DNA that is passed from mother to offspring
Mitochondria
Mitochondria can serve as a reservoir for intracellular calcium (Ca2+). T/F
T
plays a central role in the process called apoptosis or programmed cell death
Mitochondria
3 types of cytoskeleton
Thin filaments
Microtubules
Intermediate filaments
→Smallest; most abundant protein.
Main function: ELASTIC SUPPORT
THin filaments
stiff filament
➢Serve as a tubular skeletal structure in the center of each
cilium (e.g. sperm cell)
➢Compose both the centrioles and mitotic spindles of cells
undergoing mitosis
➢Act as a cytoskeleton, providing rigid physical structures for
certain parts of cells
➢Serve as the conveyor belts
Microtubules
→Strong ropelike filaments that often work together with
microtubules, providing strength and support for the fragile tubulin
structures. (Mechanical function)
Intermediate filaments
build a seal between adjacent cells and are connected to actin filaments.
Tight junctions
plaques of classical cadherins linked to the actin cytoskeleton.
Adherent junctions
desmosomal cadherins, linked to intermediate filaments.
Desmosomes
→Allow connection between the cytoplasm of two cells that are
adjacent to each other
→Helps in signaling between the cells
Gap junctions
2 cell-matrix junctions that are formed by integrins
Focal adhesion (linked to actin) and hemi-desmosomes (linked to intermediate filament)
Junctions between a cell and the extracellular matrix
Cell-matrix junction
Cellular uptake of cholesterol,
removal of receptors from the
plasma membrane, uptake of small
molecules and water into the cell,
internalization of large particles
(e.g., bacteria, cell debris)
Endosomes
Kinesins
a.k.a workhorses of the cell
Functions for transport and aids in cell replication
Kinesins transport their vesicle cargos in what direction
Orthograde difection
Together with kinesins, provide the force necessary to move
membrane-bound organelles through the cytoplasm along the
microtubular tracks.
Cytoplasmic dynein
What is the direction of cargo of cytoplasmic dynein
Retrograde
Kinesins: _______
Cytoplasmic dynein: retrograde direction
Orthograde direction
Axonemal dynein
Drives the movement of the cilium
Supplemental fluids are used in intravenous therapy to restore or maintain
normal fluid volume and electrolyte balance when the oral route may not
be possible
Intravenous solutions
have the same concentration of solutes as blood plasma
Isotonic
have lesser concentration of solutes than plasma
Hypotinic
have greater concentration of solutes than plasma
Hypertonic
Most IV fluids are isotonic. T/F
T
IV fluids Do not alter the osmolality of the vascular compartment. T/F
3 examples of isotonic fluids
NSS
D5W
Lactated ringers solution
Solution of choice for expanding the extracellular fluid (ECF) volume
because it does not enter the intracellular fluid (ICF)
NSS
Not usually used to replace electrolytes; but it is used to keep the veins
open (only if the IV fluid run at a very slow rate so that intermittently IV
medications can be injected through those lines)
D5W
Used to correct dehydration, sodium depletion, replace Gl tract fluid
losses and can also be used in fluid losses due to burns, fistula drainage,
and trauma
Lactated ringers solution
Designed to be the near-physiological solution of balanced electrolytes
○ Contains
Lactated ringers solution
Electrolyte solutions are considered isotonic if the total electrolyte content
is approximately
310 mEq/L
The perinuclear space connects to the:
a) Rough endoplasmic reticulum
b) Smooth endoplasmic reticulum
c) Golgi apparatus
d) Cell membrane
A
Thin filaments:
a) Are the desmin filaments in muscle cells
b) Compose the centrioles and mitotic spindles
c) Gives strength and support to the microtubules
d) Provide elastic support for the cell membrane
D
Thin filaments are usually found in
A. Mesoplasm
B. Ectoplasm
B
