Cell Physiology part 1-3 Flashcards
Cells were described by _______ in the mid 1600s, but it wasn’t until the 1830’s
when their importance was realized leading to the formulation of the three tenets of the
cell theory
Robert Hooke
What are the three tenets of the cell theory?
- All Organism are composed of one or more cells
- Cells are the smallest living units
- Cells arise from pre-existing cells
_______-all cells vary in shape and functions but they all share general structures
Cell diversity
What are three main regions of a cell?
Plasma membrane
Cytoplasma
Organelles
What region of a cell is this?
_____-semipermeable barrier forming the outer border
Plasma membrane
What region of a cell is this?
_____-contents of the cell including organelles and
a liquid called cytosol.
Cytoplasma
What region of a cell is this?
______-intracellular fluid, contains ions, proteins, and nutrients
Cytosol
What region of a cell is this?
____-specialized cellular structures that perform a function
Organelles
What example of region the cell is this?
____-contains the genetic material (DNA)
that functions as instructions for making proteins.
Nucleus
This is a common cell type:
Nervous tissues contain _____ and glial cells
Neurons
This is a common cell type:
_____-contain muscle cells (a.k.a. myocytes or fibers)
Muscle tissues
This is a common cell type:
_____- contain epithelial cells
Epithelial tissues
This is a common cell type:
____- contain mesenchymal cells (connective tissue stem cells), fibroblasts, fibrocytes, adipocytes (fat storage cells), chondrocytes (mature
cartilage cells), osteocytes (mature bone cells), Erythrocytes (red blood
cells), Leukocytes (white blood cells)
Connective tissues
_____-separates the living cell from its nonliving
surroundings
Plasma membrane
What general function of the plasma membrane is this?
_____-separates extracellular fluid from intracellular fluid
Barrier
What general function of the plasma membrane is this?
_____-controls what enters and exits the cell
Selective permeability
What general function of the plasma membrane is this?
_____-cell recognition, binds hormones, cell
communication
Cell maker and receptors
What general function of the plasma membrane is this?
_____-between other cell membranes or extracellular materials
Adhesion
What is the fluid mosaic model of the plasma membrane?
It’s the structure
what is the structure of the plasma membrane that has a hydrophilic head and hydrophobic tails?
Phospholipid bilayer
Part of the Phospholipid bilayer:
_____-orientate themselves towards the extracellular and
intracellular fluid
Hydrophilic heads
Part of the Phospholipid bilayer:
______-orientate themselves inward, away from the fluid
Hydrophobic tails
What does cholesterol does to the plasma membrane?
stabilizes the membrane
On top of the plasma membrane
_____-carbohydrates attached to membrane lipids and
proteins serve as biological markers recognized by leukocytes (white blood cells).
Glycocalyx
What type of protein is this?
____-attach to inner or outer surface of the membrane
Peripheral
What type of protein is this?
_____-embedded in or span the membrane
Integral membrane protein
What type of function of Transport membrane proteins is this?
______-water filled pathways that allow select ions in/out of the cell
Channel proteins
What type of function of Transport membrane proteins is this?
_____-transport select substances across the
membrane
carrier proteins
What type of function of the membrane proteins is this?
_____-play a role in anchoring cells to each
other and the cytoskeleton
Cell adhesion molecules
What type of function of the membrane proteins is this?
_____-cell recognition, cell signaling, binding of hormones
Receptors
What type of function of the membrane proteins is this?
________-facilitate chemical reactions on
inner and outer membrane surfaces
Enzymes
_______-solutes move down their concentration gradient until evenly distributed throughout
the solution
Diffusion
Factors that affect the rate of diffusion:
The magnitude of the concentration gradient
Question:
If you increase the concentration gradient, the rate of diffusion would _____.
Increase or decrease?
Increase
Factors that affect the rate of diffusion:
The permeability of the plasma membrane to a substance.
Question:
If you increase the permeability of the membrane to a substance, the rate of
diffusion would ____.
(increase or decrease)
Increase
Factors that affect the rate of diffusion:
The surface area of the membrane across which diffusion takes place
Question:
If you increase the surface area of the membrane exposed to a substance, the rate of diffusion would _______.
(increase or decrease)
Increase
Factors that affect the rate of diffusion:
The molecular weight of a substance
Question:
If you increase the molecular weight of a substance, the rate of diffusion would
______.
(increase or decrease)
Decrease
Factors that affect the rate of diffusion:
The distance through which diffusion takes place
Question:
If you increase the distance a substance must diffuse, would the rate of diffusion
______.
(increase or decrease)
Decrease
Factors that affect the rate of diffusion:
Temperature
Question:
If you increase the temperature, would the rate of diffusion?
(increase or decrease)
Increase
_____- has two types of transport passive vs. active
Plasma Membrane Transport
_________-does not require ATP to move solutes across a membrane.
Passive transport
What type of Passive transport is this?
______-solutes diffuse across the membrane unassisted
§ Small non-polar and lipid-soluble solutes
* Examples: oxygen or carbon dioxide
Simple diffusion
What type of Passive transport is this?
_____-proteins carry or assist solutes across the membrane
Charged ions move through protein channels
§ Large molecules such as glucose or amino acids are carried across by
carrier proteins
§ Carrier proteins
Ø Transports a specific substance (for example you have specific
glucose transporters in the membrane of some cells)
Ø Can reach saturation when all binding sites are occupied
(Transport maximum)
Ø Competitive inhibitor - other closely related compounds can
compete for the same binding sight
Facilitated diffusion
______- diffusion of water through a semipermeable membrane down its concentration gradient.
Osmosis
In Osmosis:
______-ability of a solution to change the shape of a cell by altering its internal
water volume, depends on concentration of non-penetrating solutes
Tonicity
In osmosis what type of tonicity is this?
*_____-contains equal concentration solutes as the cell
•- What effect would this solution have on cell volume_____
- Isotonic
- remain balance
In osmosis what type of tonicity is this?
*_____-contains more solutes than the cell
• What effect would this solution have on cell volume?
- Hypertonic
- cell shrinks
In osmosis what type of tonicity is this?
*_____-contains less solutes than the cell
• What effect would this solution have on cell volume?
- Hypotonic
- Cell will grow and eventually will rupture
______ – movement of solutes across the membrane that requires input of
energy (usually ATP). Occurs during movement of solutes against their concentration gradient or
movement of very large molecules
Active transport
Within the Active transport:
_____-proteins use ATP to transport solutes against
concentration gradient
Solute pumps
Within the Active transport:
_____-carrier proteins that transport two or more substrates across a
membrane.
§ Symport: moves two substrates in same direction
§ Antiport: moves two substrates in opposite directions
Cotransporters
Within the Active transport:
____-energy is provided directly by the hydrolysis of ATP
§ Example: Sodium-Potassium pump maintains a higher concentration of
potassium inside the cell and a higher concentration of sodium outside the
cell. Pumps 3 Na+ out and 2 K+ in.
Primary active transport
Within the Active transport:
_____-primary transport of one molecule creates an ion
gradient used to drive another molecule against its concentration gradient.
§ Example: Movement of sodium down its concentration gradient is used to
drive glucose into a cell against its concentration gradient (sodium and
glucose both move into the cell through a symport cotransporter).
Secondary active transport
_____-moves material from cell interior to the extracellular space.
o Vesicles fuse with the plasma membrane expelling the contents out of the cell
Exocytosis
_____-moves material from extracellular space to cytoplasm.
o Phagocytosis – “cell eating”
o Pinocytosis – “cell drinking”
o Receptor mediated endocytosis – receptors bind specific substances and initiates
endocytosis.
Endocytosis
______-control center of the cell, contains chromosomes made of chromatin
Nucleus
Within the nucleus
______-strands of DNA (genetic material) bound to proteins
Chromatin
Within the nucleus
____-double membrane separating the
nucleus from the cytoplasm
Nuclear envelope (a.k.a. nuclear membrane)
Within the nucleus:
____-dark stained body, site of ribosome production
Nucleolus
That process of DNA becoming to messenger RNA to protein is called?
Central Dogma of Genetics
____-occurs in the nucleus the sequence of nucleotides in the
DNA coding for a gene are read and used to guide the synthesis of a messenger
RNA copy of the gene with a corresponding nucleotide sequence
Transcription
____-occurs at ribosome when sequence of messenger RNA is read and
used to guide the synthesis of a protein
Translation
_____-small dark bodies made of protein and RNA
• Site of protein synthesis (translation)
• Found free in the cytoplasm and attached to rough endoplasmic reticulum
Ribosomes
_____-fluid-filled coiled tubules. Serves as a channel for transporting substances within the cell.
Endoplasmic reticulumn (ER)
What type of Endoplasmic reticulumn (ER) is this ?
_______ ER
*Studded with ribosomes
o Manufactures all secreted proteins
Rough ER
What type of Endoplasmic reticulumn (ER) is this ?
_______ ER
o Functions in lipid metabolism and cell signaling
Smooth ER
_____-stack of flat membranous sacs
• Packages proteins for transport depending on their final destination
Golgi apparatus
______-small membranous compartments bud off of the cell membrane, nucleus, ER
and golgi apparatus.
Vesicles
What type of the three distinct pathways of the vesicles is this?
____-release content by exocytosis
Secretory vesicles
What type of the three distinct pathways of the vesicles is this?
_____- fuses with cell membrane
Membrane renewal vesicles
What type of the three distinct pathways of the vesicles is this?
Become ___________ and remain in cytoplasm
lysosomes or peroxisomes
______-specialized vesicles containing proteolytic digestive enzymes
• Digest proteins from non-usable and damaged organelles
• Destroy bacteria and other foreign materials within the cell
Lysosome
_______-specialized vesicles containing oxidase enzymes
• Detoxify harmful substances like alcohol and formaldehyde
• Break down free radicals (highly reactive chemicals)
Peroxisome
______-double membrane structures
• Infoldings of inner membrane are called cristae
• Inner fluid called the matrix
• “Powerhouses” of the cell provides ATP for cellular energy
• Contains it’s own circular DNA for reproduction and protein synthesis
Mitochondrion
______-“cell skeleton”. Provides the cell with an internal framework,
supports organelles, and facilitates intracellular motility
Cytoskeleton
What type of cytoskeleton is this?
________-Hollow tubes made of protein
o Radiate out from a region near the nucleus
o Anchor and move organelles
o Form mitotic spindles during cell division
o Largest diameter of the “cell skeleton” elements
Microtubules
What type of cytoskeleton is this?
______-Concentrated under the plasma membrane
o Function in cell mobility and shape
o Braces plasma membrane and strengthens cell surface
o Smallest diameter of the “cell skeleton” elements
Microfilament
What type of cytoskeleton is this?
________-Composed of proteins with high tensile strength
o Resist pulling forces on the cell
Intermediate filaments
_______-Located near the nucleus
• Directs the formation of microtubules
• Important role in enabling the movement of chromosomes during cell division
• Consists of a pair of 50)__________________- Rod-shaped bodies composed of
short microtubules and other proteins arranged in a cylindrical structure
Centrosomes (which are pairs of centrioles)
50) Centrioles
What type of the extension of the cell membrane is this?
________-whip-like extension that occurs on the free surface of the cell
o Move substances along cell surface
o Found on epithelial cells lining most of the respiratory tract
Cilia
What type of the extension of the cell membrane is this?
______-similar whip-like extensions but much longer
o Tail of sperm is only example in human anatomy
o Functions to propels the cell itself
Flagella
What type of the extension of the cell membrane is this?
_____-small finger-like extensions that increase surface area
o Found on epithelial cells lining the intestines and tubules of the kidney
Microvilli
_______-form an impermeable barrier between cells by interlocking
proteins encircling the cell
• Found at the apical surface of epithelial cells
• Keeps out enzymes, acids, microorganisms
Tight Junction
_____-anchor intermediate filaments of adjacent cells together
• Prevent cells that are subjected to mechanical stress from being pulled apart
Desmosomes
______-cells are connected by hollow cylinders
• Allows chemical communication between cells
• Found in smooth and cardiac muscle
Gap Junctions
