Chapter Three: Cell Biology Flashcards
Cell theory
- All living organism are comprised of one or more cells
- The cell is the basic unit of structure, function, and organization in all organisms
- All cells come from existing, living cells
What are the three major parts of a cell?
Plasma membrane, cytoplasm and nucleus
What is the role of the plasma membrane?
Creates a boundary
What are the six functions of membrane products?
Transport
Signal transduction
Attachment
Enzymes
Intercellular joining
Cell to cell recognition
What is the function of integral membrane proteins?
Transport proteins, enzymes, receptors
What is the function of peripheral proteins?
Help the cell move during cellular division and muscular contraction
The plasma membrane seperates __ from __
Intracellular fluid from extracellular fluid
Membrane lipids are 75% __, 5%__, and 20 % ___
Phospholipids, glycolipids, and cholesterol
Phosphate heads are polar and hydro__
hydrophilic
phospohate heads are __ (polar/nonpolar) and hydrophilic
Polar
Fatty acid tails are __ (polar/nonpolar) and hydrophobic
nonpolar
Fatty acid tails are nonpolar and hydro__
hydrophobic
What function does cholesterol preform in membrane lipids?
increases the stability of the membrane
What is the primary function of membrane proteins?
Allow communication with the environment
What are the two types of membrane proteins?
Integral proteins and peripheral proteins
Integral proteins
– Firmly inserted into __
– Have hydrophobic and hydrophilic regions
* Can interact with __ tails and water
– Function as __ proteins (channels and carriers), enzymes, or receptors
Membrane
lipid tails
transport proteins
Peripheral proteins
– Loosely attached to ___ proteins
– Include filaments on intracellular surface for membrane __
– Function as __ ; motor proteins for shape change during cell division and muscle contraction; cell-to-cell connections
integral
support
enzymes
Which protein is being described?
– Loosely attached to integral proteins
– Include filaments on intracellular surface for
membrane support
– Function as enzymes; motor proteins for shape change during cell division and muscle contraction; cell-to-cell connections
Peripheral proteins
Which protein is being described?
– Firmly inserted into membrane (most are
transmembrane)
– Have hydrophobic and hydrophilic regions
* Can interact with lipid tails and water
– Function as transport proteins (channels and
carriers), enzymes, or receptors
Integral proteins
The Glycocalyx
“Sugar covering” at cell surface
- Lipids and proteins with attached carbohydrates
Allows immune system to recognize “self” and
“non self”
What are three ways cells are bound?
Tight junctions
Desmosomes
Gap junctions
Tight junctions
Integral proteins fuse together to prevent fluids and molecules from moving between cells
Desmosomes
Anchor cells together at plaques that reduce the possibility of tearing
Plaques in a cell
Thickenings on plasma membrane
“Molecular velcro”
Gap junctions
Communication junctions allow small molecules to pass from cell to cell
Plasma membrane allows a cell to
- maintain a boundary
- obtain exactly what it needs from interstitial fluid
interstitial fluid is comprised of
thousands of miscellaneous substances
ie: amino acids, sugars, fatty acids, vitamins, hormones, salts, waste products, etc.
Plasma membranes are __ permeable
selectively
- Some molecules pass through easily; some do not
What are two ways substances cross a membrane?
- Passive processes
- Active processes
– No cellular energy (ATP) required
– Substance moves down its concentration gradient
Passive processes/transport
– Energy (ATP) required
– Occurs only in living cell membranes
Active processes/transport
What type of transport requires ATP?
Active
What are the two types of passive transport?
diffusion and filtration
Molecule will passively diffuse through a membrane if:
- It is lipid soluble
- Small enough to pass through membrane channels
- Assisted by carrier molecule
Filtration is usually across __ walls
capillary
Which passive processs is this describing?
Nonpolar lipid-soluble (hydrophobic)
substances diffuse directly through
phospholipid bilayer
Simple diffusion
Which passive process is this describing?
Certain hydrophilic molecules (e.g.
glucose, amino acids, and ions)
transported passively by
– Binding to protein carriers
– Moving through water-filled channels
- Selectively transport ions or water
Facilitated diffusion
What is the difference between leakage channels and gated channels?
Leakage channels are always open, gated channel are controlled by chemical or electrical signals
movement of water through a semi-permeable membrane from from a high concentration of water to a low concentration of water
Osmosis
Tonicity
Ability of solution to alter cell’s water volume
Isotonic
Solution with same non penetrating solute concentration as cytosol
Hypertonic
Solution with higher non- penetrating solute concentration than cytosol
Hypotonic
Solution with lower non-
penetrating solute concentration than cytosol
Is this showing an isotonic, hypertonic, or hypotonic solution?
Isotonic
Is this showing an isotonic, hypertonic, or hypotonic solution?
Hypertonic
Is this showing an isotonic, hypertonic, or hypotonic solution?
Hypotonic
Which energy source does simple diffusion utilize?
Kinetic energy
Which energy source does faciliatated diffusion utilize?
Kinetic
Which energy source does osmosis utilize?
Kinetic
What are the two different types of active processes?
Active transport and vesicular transport
Both Active transport Vesicular transport require __ to move solutes across a living plasma membrane
ATP
Active or passive transport?
Moves solutes against concentration gradient and requires carrier proteins
Active
Primary active transport requires energy directly from ___ ___
ATP hydrolysis
Secondary active transport requires energy __ from ionic gradients
created by primary active transport
indirectly
What type of transport is this describing?
Energy from hydrolysis of ATP causes shape change in transport protein that “pumps” solutes (ions) across membrane
Primary Active transport
Sodium - Potassium pump
Carrier (pump) called Na+-K+ ATPase and is involved in primary and secondary active transport of nutrients and ions
Antiport system
Substances transported in opposite directions
Symport system
Substances transported in the same direction
Cotransport
transports multiple substances simultaneously
Vesicular transport requires
ATP
Vesicular transport
transportation of large particles, macromolecules, and fluids across membranes in sac called vesicles
Exocytosis
exit the cell
Endocytosis
enter the cell
transcytosis
enter the cell, transport across and out of the cell
vesicular trafficiking
transporting from one part of the cell to another part of the cell
Endocytosis and Transcytosis
* Involve formation of __ vesicles
* Often ___ mediated, therefore very selective
Protein coated
receptor
Pharocytosis
pseudopods engulf solids and bring them into a cell’s interior
ie. pseudpods snatch up solids and brings them inside the cell
cell snatching
phagosome
visicle formed by phagocystosis
Pinocytosis
Fluid-phase endocytosis
- plasma membrane infolds and brings extracellular fluid inside the cell to “sample” the environment
- fuses with the endosome
pino = pino grigio = a lil sippy sample
Receptor-mediated endocytosis allows __ endocytosis and transcytosis
specific endocytosis and transcytosis
Provides the main route for endocytosis and transcyotosis
clathrin-coated pits
Exocytosis is usually activated by __
cell-surface signal or change in membrane voltage
where are v-SNARES found
vesicle
v for vesicle
where are t-SNARES found
cell membrane
t for target
The 4 part process of exocytosis
- visicle migrates to plasma membranes
- v-SNARES bind with t-SNARES
- vesicle and plasma membrane fuse
- vesicle contents are released to the outside of the cell
This photo is demonstrating which phenomenon?
exocytosis
Where is cytoplasm found?
between the plasma membrane and the nucleus
What three things make up the cytoplasm?
cytosol
organelles
inclusions
What is cytosol?
water with solutes
proteins, salts, sugars, etc.
what are organelles?
metabolic machinery of cell - each have a specific function and are either membranous or nonmembranous
Membranes allow crucial ____
Compartmentalization
Membranous or nonmembranous
- Nucleus
- Mitochondria
- Peroxisomes
- Lysosomes
- Endoplasmic reticulum
- Golgi apparatus
Membranous
Membranous or nonmembranous?
- Cytoskeleton
- Centrioles
- Ribosomes
Nonmembranous
- Largest organelle; genetic library with blueprints for nearly all cellular proteins
- Responds to signals; dictates kinds and amounts of proteins synthesized
Nucleus
The __ is the largest organelle
Nucleus
- Dark-staining spherical bodies within nucleus
- Involved in rRNA synthesis and ribosome subunit assembly
Nucleoli
The ___ contains the DNA coding for rRNA
Nucleoli
What provides most of the cell’s ATP?
Mitochondria
Ribosomes
granules containing protein and rRNA
- site of prtoein synthesis!
Two types of endoplasmic reticulum (ER)
rough and smooth er
What organelle is being described?
- Manufactures all secreted proteins
- Synthesizes membrane integral proteins and phospholipids
Rough ER
What organelle is being described?
enzymes (integral proteins) function in – Lipid metabolism; cholesterol and steroid-based hormone synthesis; making lipids of lipoproteins
– Absorption, synthesis, and transport of fats
– Detoxification of drugs, some pesticides, carcinogenic chemicals
– Converting glycogen to free glucose
– Storage and release of calcium
Smooth ER
What is the function?
Golgi apparatus
modifies concentrates and packages proteins and lipids from the rough ER
What organelle is being described?
Peroxisomes
- detoxify harmful/toxic substances
- sacs that contatin oxidases and catalases
- neutralize free radicals
What organelle is being described?
- digestive enzymes
- digest bacteria, viruses and toxins
- break down and release glycogen
Lysosomes
What is the overall function of the endomembrane system?
produce, degrade, store, and export biological molecules
- includes ER, golgi apparatus, secretory vesicles, lysosomes, nuclear and plasma membranes
Label the diagram
Transport vesicle
Plasma membrane
Lysosome
Secretory vesicle
Smooth ER
Rough ER
Golgi apparatus
Nuclear envelope
nucleus
a. nuclear envelope
b. nucleus
c. smooth ER
d. rough ER
e. secretory vesicle
f. golgi apparatus
g. plasma membrane
h. transport vesicle
i. lysosome
Cytoskeleton
series of rods throughout the cytosol
- proteins link rods to other cell structures
Microfilaments, intermediate filaments, and microtubules are all correlated with __
the cytoskeleton
Microfilaments function
- give strength
- involved in cell motility, change in shape, and endocytosis and exocytosis
actin
What are microfilaments comprised of?
actins, which are protein subunits
what are intermediate filaments? what are they comprised of?
tough ropelike protein fibers that attach to desmosomes to resist pulling forces on cells
comprised of tetramer fibrils
Microtubules
comprised of tubulins and determine overall cell shape and distribution of organelles
mitochondria, lysosomes, and secretory vesicles attach to the microtubules and are moved throughout the cell by motor proteins
motor proteins
- powered by atp
- proteins that assist in motility
basically cars
contains genetic material (DNA) and controls the cell’s activities by regulating gene expression
Nucleus
produces energy through cellular respiration
Mitochondria
synthesizes proteins
Ribosomes
transports proteins and lipids, and is involved in protein folding and modification
Endoplasmic reticulum (ER)
modifies, sorts, and packages proteins and lipids for transport
Golgi apparatus
contains digestive enzymes that break down and recycle cellular waste
Lysosomes
breaks down fatty acids and detoxifies harmful substances
Peroxisomes
stores water, nutrients, and waste
Vacuoles
converts sunlight into energy through photosynthesis
Chloroplasts (found in plant cells)
provides support and structure to the cell, and is involved in cell division and movement.
Cytoskeleton
