Name the basic functions that all cells share.
cell metabolism, transport of substances through the cell,
communication and cell reproduction.
What is the cell surrounded by? What is its function?
Plasma Membrane - it regulates exchange between the cell and the
environment, provides structural support, and physically isolates the
cell from its surroundings.
The plasma membrane separates the fluid in the body into two
compartments. What are they?
Extracellular fluid (ECF) and Intracellular fluid (ICF) or cytosol.
What are the components of the cytosol?
cytosol, organelles, and cytoskeleton.
What is the function of the cytosol?
The site of many important cellular reactions, including those of
glycolytic catabolism.
What are organelles?
The tiny cellular structures that compartmentalize the cell's functions.
What is the cytoskeleton?
Consists of long protein filaments that support the cell, help it
maintain its shape, allow substances to be transported within the
cell, and can move the cell.
What is the nucleus?
The membrane-bounded organelle that houses most of the cell's DNA
(deoxyribonucleic acid) and controls many of the cell's functions.
What makes up the plasma membrane?
phospholipid bilayer
How is the phospholipid bilayer arranged?
The phospholipids are arranged so their hydrophilic phosphate heads
face the water-containing cytosol and ECF, and their hydrophobic fatty
acid tails face one another within the bilayer.
What is the fluid mosaic model?
The plasma membrance is a fluid, dynamic structure with multiple
components moving laterally within the plane of the phospholipid bilayer.
What is an integral protein?
Proteins embedded in the membrane, with transmembrane proteins
spanning its width.
What are peripheral proteins, where are they located?
They are found on one side of the membrane only. Membrane proteins
may function as channels, carriers, enzymes or receptors. They may
also provide structural support to cells and tissues.
What does selectively permeable mean? Is the phospholipid bilayer
selectively permeable?
Allowing certain molecules to cross it while prohibiting the passage
of other molecules. Yes, the phospholipid bilayer is selectively permeable.
What is the transporting of substances across the membrane with no
ATP expenditure?
Passive transport
What is the transporting of substances across the membrane requiring ATP?
Active transport
A type of passive transport during which molecules move down their
concentration gradient until equilibrium is reached.
Diffusion
The movement of molecules directly through the phospholipid bilayer.
Simple diffusion
The movement of polar and ionic molecules across a membrane through a
protein channel or with the help of a carrier protein.
Facilitated diffusion
The type of passive transport in which water (the solvent) moves
across across a selectively permeable membrane from a region of lower
solute concentration to a region of higher solute concentration until
equilibrium is reached.
Osmosis
What is the basic force that drives osmosis, which is the pressure of
solute molecules in a solution that exert a "pulling" force
on water molecules.
Osmotic pressure
What is the concept that describes the osmotic pressure of one
solution relative to another?
tonicity
What is a solution that has the same osmotic pressure as the cytosol
and results in no net movement of water by osmosis?
Isotonic extracellular solution
What is a solution that has a higher osmotic pressure than the
cytosol and causes water to move out of the cell by osmosis?
a hypertonic extracellular solution
What is a solution that has a lower osmotic pressure than the cytosol
and causes water to enter the cell by osmosis?
A hypotonic extracellular solution
What are specialized components within the cell that carry out
specific functions?
Organelles
What happens during a primary active transport?
A membrane protein uses the energy from ATP to "pump" a
solute against its concentration gradient. One of the body's main
active transport pumps is the NA+/K+ pump, or ATPase, which pumps
three sodium ions out of and two potassium ions into the cell.
What is one of the body's main active transport pumps?
Sodium/Potassium pump, it pumps three sodium ions out of and two
potassium ions into the cell.
What uses a primary transport pump to create a concentration
gradient, and then uses potential energy from that concentration
gradient to pump another solute into or out of the cell against its
concentration gradient?
Secondary active transport
What is the study of membrane potential?
Electrophysiology
What is a type of active transport process that allows large
molecules to enter or exit a cell packaged in membrane bounded vesicles?
Vesicular transport
The process by which large molecules enter the cell? (moving into the cell)
Endocytosis
What are the two main types of endocytosis?
Phagocytosis AND Pinocytosis
Specialized cells ingest large substances such as bacteia or dead
cells. (cell eating)
Phagocytosis
During what phase of endocytosis do coated pits in the plasma
membrane form vesicles containing dissolved substances from the ECF?
(cell drinking)
Pinocytosis
The process by which large molecules exit the cell. The molecules are
packagedd into a vesicle that fuses with the plasma membrane,
releasing the molecules into the ECF, a process known as secretion.
(moving out of the cell)
Exocytosis
What are specialized components within the cell that carry out
specific functions.
Organelles
What produces the bulk of the cell's chemical energy in the form of
ATP? Synthesizes most of the cell's ATP.
Mitochondria (mitochondrion)
What uses oxygen to carry out oxidation of toxic substances and fatty
acids, and synthesis of certain phospholipids? Contains enzymes that
oxidize toxin and fatty acids.
Peroxisomes
Small, granular organelles with two subunits that synthesize
proteins. Granular structure that makes proteins.
Ribosomes
A large branching network of tubules and sacs that enclose a single space.
Endoplasmc reticulum
What has ribosomes attached to its surface, and it modifies and folds
proteins into the correct structure, made by those ribosomes. It also
makes new proteins for secretion and for the plasma membrane and other
cellular membranes?
Rough ER
What has no ribosomes on its surface, stores calcium, synthesize many
lipids, and detoxifies certain substances? Detoxifies certain
chemicals, makes lipids, stores calcium ions.
Smooth ER
What is a stack of flattened sacs, it receives vesicles from the ER,
and then modifies and packages these products to be secreted from the
cell by exocytosis, to become part of the plasma membrane, or to be
incorporated into lysosomes? Modifies, packages, and sorts proteins.
Golgi apparatus
What contains digestive enzymes that break down substances taken into
the cell by endocytosis, as well as worn-out organelles? They are
produced in the golgi apparatus.
lysosomes
What consists of three types of protein filament tht are made from
smaller protein units?
Cytoskeleton
What are the functions of the cytoskeleton?
1) giving the cell its characterisstic shape and size
2) supporting the plasma membrane and nucleus
3) moving substances within the cell with the use of associated
motor proteins
4) dividing the cell
5) moving the cell
Small filaments composed of protein. They provide structural support
to the cell.
Actin filaments
What two proteins together change the shape and size of the cell
during enocytosis, exocytosis, cytokinesis, and muscle contraction.
They also enable certain cells to migrate within the body.
Actin and myosin
Ropelike filaments made of proteins (especially keratin) that bend
easily but are very strong and resist breaking. They provide the cell
with mechanical strength and support for its organelles and overall structure.
Intermediate filaments
The largest filaments, they are hollow tubes made of protein subunits
called tubulins. They support the cell, hold the organelles in their
proper places, move organelles within the cell, and from cilia and
flagella on certain cells.
Microtubules
The plasma membrane of some cells are foled into extensions, which
increase the surface area of the membrane for functions such as absorption.
Microvilli
Hairlike projections found on the surfaces f certain cells. They beat
in unison to sweep substances past the cell.
Cilia
Single projections that propel the cell itself. Sperm are the only
flagellated cells in the human body.
Flagella
Contains most of the cell's DNA and is the control center of the cell
The nucleus
The nucleus is surrounded by a double membrane.
Nuclear envelope
Regions of the nucleus that are responsible for both the synthesis of
RNA molecules suchas ribosomal RNA and the assembly of ribosomes.
Nucleoli
The process bu which the cell uses instructions in the DNA to buld proteins.
Protein synthesis
A segment of DNA that specifies the amino acid sequence of a single
protein. Each amino acid is specified by a three-nucleotide-long
"word" called a triplet.
A gene
A list of amino acid is specifie by each possible codon.
The genetic code
The cell copies the information in the gene into a mRNA transcript
with the help of the enzymes RNA polymerase. It consists of three
stages - initiation, elongation, and termination.
transcription
During this process the code in the mRNA transcript of a gene is
translated into the amino acid sequence of a particular polypeptide.
Takes place on a ribosome. It consists of three stages - initiation,
elongation, and termination.
Translation
What happens during Interphase?
G1 - the cells grows and rapidly synthesizes proteins
S - cell synthesizes or replicates it DNA
G2 - the cell makes proteins necessary for cell division
What are the phases of mitosis?
Prophase, Metaphase, Anaphase, Telophase
Describe prophase?
The replicated sister chromatids condense, the nuclear envelope
breaks apart, and the mitotic spindle forms and attaches to the
centromere of each chromatid.
Describe Metaphase?
The spindle fibers pull the sister chromatids to align along the
equator of the cell. Meet in the middle.
Describe Anaphase?
The sister chromatids separate and chromosomes are pulled to opposite
poles of the cell by the spindle fibers. Apart
Describe Telophase?
The two daughter cells' chromosomes reassume the loose structure of
chromatin. The end.
What occurs simultaneously with anaphase and telophase; it divides
the cytoplasm between the daughter cells and pinches the cell in two
at the cleavage fourrow?
Cytokinesis
A channel protein that only accepts one type of molecule? One solute
moving in one direction - (Na+)
Uniporter
A channel protein that has 2 types of molecules that moves in one
direction. Two solutes moving in one direction (Na+/glucose)
Symporter (co-transport)
A channel protein that has 2 types of molecules moving in opposite
directions. Two solutes moving in opposite directions. Moving 3 Na+
out and 2 K+ in.
Antiporter (counter transport)
If a cell is put into a hypertonic solution. What will happen?
The cell will shrivel (creanate)
If a cell is put into a hypotonic solution. What will happen?
The cell with sell (lyse)
What holds calcium (Ca2+)?
The SER in muscle tissue holds calcium.
What is mRNA - tRNA? Where does it happen?
Translation, happens outside of the nucleus
What is DNA - mRNA? Where does it happen?
Transcription, happens inside the nucleus
What is used to transport cholesterol?
receptor-mediated endocytosis