Anatomy/ cell structure
Materials inside the cell are ___ and
those outside are ___.
inside - intracellular
oitside - extracellular
• also termed the plasma membrane
• a structure that encloses the cytoplasm
cell membrane
• jelly-like substance that holds organelles
cytoplasm
• specialized structures in cells that perform
• specific functions
• Example: nucleus, mitochondria, ribosomes
organelles
is the
outermost component of a cell.
cell membrane or plasma membrane
model used to
describe the cell membrane structure.
fluid-mosaic model
It forms a boundary between material in inside
the cell and the outside.
It acts as a selective barrier.
cell membrane
membrane contains
phospholipids,
cholesterol, proteins, and carbohydrates.
Phospholipids contain 2 regions:
polar and nonpolar
form a bilayer.
Phospholipids
exposed to water around the
membrane.
polar region
facing the interior of the
membrane.
nonpolar region
A phospholipid molecule has a polar head region
that is hydrophilic and a nonpolar tail region that
is hydrophobic.
polar head-hydrophilic, nonpolar tail - hydrophobic
it has a selective permeability,
which allows only certain substances to pass in
and out of the cell.
cell membrane
Substances such as: are found in higher concentrations
____the cell.
sodium, calcium, and
chloride.
outside
Substances such as: are found in higher concentrations
_____ the cell.
enzymes, glycogen, and
potassium.
inside
substances that can pass
directly through the cell membrane’s
phospholipid bilayer.
O2 and CO2
does not require
the cell to expend energy.
does require the
cell to expend energy, usually in the form of ATP.
passive membrane transport
active membrane transport
mechanisms
include diffusion, osmosis, and facilitated
diffusion.
mechanisms include
active transport, secondary active transport,
endocytosis, and exocytosis.
passive membrane transport
active membrane transport
Passive membrane transport mechanisms
include:
Active membrane transport mechanisms include
diffusion, osmosis, and facilitated
diffusion.
active transport, secondary active transport,
endocytosis, and exocytosis.
generally involves movement of substances in a solution down a concentration gradient.
diffusion
A solution is generally composed of two major parts,
solutes and the solvent.
_____ are substances dissolved in a predominant liquid or gas, which is called the ____
solutes
solvent
can diffuse directly through the phospholipid bilayer.
lipid soluble substances
such as ions can
diffuse across the cell membrane only by passing
through cell membrane channels.
water- soluble substances
Two classes of cell membrane channels include leak channels and gated channels.
Leak channels - constantly allow ions to pass
through.
Gated channels - limit the movement of ions
across the membrane by opening and closing.
force required to prevent
movement of water across cell membrane
osmotic pressure
the diffusion of water (a solvent)
across a selectively permeable membrane from
a region of higher water concentration to one of
lower water concentration
osmosis
depends on the difference of
solution concentrations inside a cell relative to outside the cell.
osmotic pressure
If the cell Swells Enough, It Can Rupture, a process called LYSIS.
hypotonic
The cell will NEITHER SHRINK NOR SWELL.
isotonic
Water moves by osmosis from the cell into the hypertonic solution, resulting in cell Shrinkage, Or Crenation
hypertonic
Carrier-mediated transport mechanisms include:
Facilitated diffusion and Active transport
does NOT REQUIRE ATP for
energy.
does Require ATP for transport.
facilitated diffusion
active transport
are proteins within the cell
membrane involved in carrier mediated
transport.
carrier molecule
These substances include amino acids, glucose, and some polar molecules produced by the cell.
carrier - mediated transport
A major example of active transport is the action of
sodium - potassium pump
uses the energy
provided by a concentration gradient
established by the active transport of one
substance, such as Na+
to transport other
substances
secondary active transport
diffusing substance MOVES IN THE SAME DIRECTION as the initial active
transported substance.
diffusing substance
Moves In A Direction Opposite to that of the
initial active transported substance.
cotransport
counter transport
process that that brings materials into cell using vesicles.
endocytosis
Exocytosis involves the use of membrane-bound sacs called _____ that accumulate materials for release from the cell.
secretory vesicles
The vesicles move to the cell membrane and fuse, ultimately releasing the material by ____.
exocytosis
The interior of a cell is composed of the ______, which a jelly-like fluid that surrounds the organelles.
cytoplasm
specialized structures that perform
certain functions.
organelles
organelles include 12:
nucleus, ribosomes,
endoplasmic reticulum, Golgi apparatus, lysosomes,
peroxisomes, mitochondria, cytoskeleton,
centrioles, cilia, flagella, and microvilli.
is a large organelle usually located
near the center of the cell.
nucleus
nuclei of human cells contain
23 pairs of chromosomes which consist of DNA and proteins.
chromosomes are loosely coiled and collectively called
chromatin
its a components that are produced in the nucleolus.
ribosomes
Ribosomes that are not attached to any other organelle are called_____
free ribosomes
the organelles where proteins
are produce
ribosomes
is a series of
membranes forming sacs and tubules that
extends from the outer nuclear membrane into
the cytoplasm.
endoplasmic reticulum (ER)
involved in protein synthesis and
is rough due to attached ribosomes.
Rough ER
has no attached ribosomes and
is a site for lipid synthesis, cellular detoxification,
and it stores calcium ions in skeletal muscle
cells.
smooth ER
It collects, modifies, packages, and distributes proteins and lipids manufactured by the ER.
golgi apparatus
also called the Golgi
complex, consists of closely packed stacks of
curved, membrane-bound sacs.
golgi apparatus
vesicles, some of
which are secretory vesicles, lysosomes, and
other vesicles.
golgi apparatus
contain a variety of enzymes that function as intracellular digestive systems.
lysosomes
membrane-bound vesicles
formed from the GOlGI APPARATUS
lysosomes
is a by-product of fatty acid and amino acid breakdown and can be toxic to a cell.
hydrogen peroxide
small, membrane-bound
vesicles containing enzymes that break down
fatty acids, amino acids, and HYDROGEN PEROXIDE
(H2O2
).
peroxisome
it have an inner and outer membranes that separated by a space.
mitochondria
are small organelles responsible for producing considerable amounts of ATP by aerobic (with O2 )metabolism
mitochondria (singular mitochondria)
Outer membranes have a SMOOTH CONTOUR, but
the Inner membranes have NUMEROUS FOLDS, called
CRISTAE, which project into the interior of the
mitochondria
mitochondria
The material within the inner membrane is the MITOCHONDRIAL MATRIX and CONTAINS ENZYMES and mitochondrial DNA (mtDNA).
mitochondria
It consists of protein structures that support the cell, hold organelles in place, and enable the cell to change shape.
cytoskeleton
gives internal framework to the
cell.
cytoskeleton
protein structures in cytoskeleton are:
microfilaments
intermediate filaments
microtubules
microtubules forming
essential components of certain organelles, such
as
cilia and flagella
hollow structures formed from
protein subunits.
microtubules
small fibrils formed from
protein subunits that structurally support the
cytoplasm, determining cell shape.
microfilaments
-provide mechanical support to the cell.
-fibrils formed from
protein subunits that are smaller in diameter than
microtubules but larger in diameter than
microfilaments.
intermediate filaments
specific type of intermediate filament is _____
keratin
is a specialized area of
cytoplasm close to the nucleus where
microtubule formation occurs.
centrosome
involved in the process of
mitosis.
centrioles
carrier-mediated transport process that moves substances across the cell membrane from an area of higher concentration to an area of lower concentration of that substance.
facilitated diffusion
- project from the surface of certain cells.
- responsible for the movement of
materials over the top of cells, such as mucus
cilia
cylindrical structures that extend from the cell and are composed of microtubules.
cilia
have a structure similar to that of cilia but are much longer, and they usually occur only ONE PER CELL.
flagella
- numerous on cells that have them and
they increase the surface area of those cells.
specialized extensions of the cell
membrane that are supported by microfilaments.
microvilli
A DNA molecule consists of ____ joined together to form two nucleotide strands.
nucleotides
Each nucleotide consists of:
5-carbon sugar, a phosphate group, and a nitrogenous base.
Gene expression, which is protein synthesis, involves
transcription and translation.
Transcription involves copying DNA into
messenger RNA.
Translation involves messenger RNA being used
to produce a protein.
h
takes place in the nucleus of the
cell.
transcription
DNA contains one of the following organic bases:
Messenger RNA (mRNA) contains
DNA -thymine, adenine, cytosine, or guanine
RNA- uracil, adenine,
cytosine, or guanine.
occurs in the cell cytoplasm after
mRNA has exited the nucleus through the
nuclear pores.
translation
Codons (3 nucleotide bases) on the mRNA are
read by anticodons (3 nucleotide bases) on
transfer RNA (tRNA).
g
cell cycle includes two major phases:
nondividing phase called INTERPHASE
dividing phase called MITOSIS
Replication of DNA gives two identical CHROMATIDS joined at a centromere; both form one chromosome.
D
involves formation of 2 daughter cells from a single parent cell.
mitosis
Mitosis is divided into four phases:
1.prophase
2. metaphase
3 anaphase
4. telophase.
During this phase the CHROMATIN condenses to
form visible chromosomes.
prophase
termed spindle fibers, form to
assist in breaking the centromere between the
chromatids and move the chromosomes to
opposite sides of the cell
microtubules
During this PHASE, the chromosomes ALIGN NEAR
THE CENTER of the cell.
metaphase
the chromatids separate and each CHROMATID IS CALLED
chromosome
during ____the chromosomes in each of the daughter cells become organized to form two separate nuclei, one in each newly formed daughter cell.
telophase
begin to unravel and resemble
the genetic material during interphase
telophase
The process by which cells develop with specialized structures and functions is called
differentiation
diversity of cell type
bone cells
nerve cells
muscle cells
red blood cell
termed programmed CELL DEATH, is a normal process by which cell numbers within various tissues are adjusted and controlled.
apoptosis
There are various causes for cellular aging.
• Existence of a cellular clock
• Presence of death genes
• DNA damage
• Formation of free radicals
• Mitochondrial damage
Cellular Aspects of Aging
There are various causes for cellular aging.
• Existence of a cellular clock
• Presence of death genes
• DNA damage
• Formation of free radicals
• Mitochondrial damage
Some tumors are benign and some are____
- can spread by a process,
termed metastasis.
malignant (cancer)
malignant tumors
-abnormal proliferations of cells.
-due to problems occurring in the cell
cycle.
tumors