The Cell & Cell Structure Flashcards
two main factors that cause HL
Infants may be born with hearing loss caused by a viral infection that was acquired during pregnancy - an environmental factor
At other times, the cause is genetic; the development of the auditory-vestibular system depends on sequential activation of multiple genes, problems with any one gene can cause a genetic hearing loss
How many genes need to be affected to cause a genetic HL
just one
something that happens later in life, after birth, environmental thing
meningitis - causes HL and can become deaf in one or both ears
Acquired HL
inherited it from parents and could be born with it or it could happen later in life
some cancer genes, but breast cancer is in older girls
genetic HL
why is HL complex?
because the process of hearing is complex
can HL be a combo of genetic and environmental factors?
YES
more susceptible to antiobiotics for example
How can understanding genetic causes of HL be important?
knowledge allows dr’s to inform families about chances of having children with HL and influences the way the HL is treated.
if person’s HL will get worse, sometimes predicted if the specific cause of it is known
syndromic condition
two or more systems are affected
nonsyndromic conditions
only one system is affected
is it common for kids to have genetic HL even if the parents do not?
YES
HL can be passed onto future generations
Why should we study cell biology in a genetics course in audiology?
The cell is the basic unit of structure and function in all organisms
Genes control the shape, size, and function of cells
The study of cell structure and function helps us understand how genetic disorders disrupt the cellular processes
two main types of cells
prokaryotic and eukaryotic cells
have a plasma membrane (cell wall) but do not have a membrane-bound nucleus or other membrane-bound organelles (little organs - structures within cells)
prokaryotic cells
little organs - structures within cells
membrane-bound organelles
typically unicellular cells
most bacteria are this
prokaryotic cells
DNA is found in a coiled loop (chromosome) floating in the cytoplasm
prokaryotic cell
posses both a plasma membrane and nuclear membrane along with other organelles
eukaryotic cells
nucleus has dna
eukaryotic cells
all large complex species including humans have these cells
eukaryotic cells
where are human chromosomes found?
in the nucleus
body
soma
cells that differentiate into tissues and organs the body
somatic cells
Cells from which a new organism can develop
egg and sperm
germ cells
everything but your sex cells
cannot build new life
somatic cells
which cells can build a new life
organisms develop from here
germ cells
what are cells formed from
molecules
The last common ancestor of life on earth was
the closest thing to an autonomous biologic unit
cell
what do all cells use
same molecular building blocks
Similar methods for storage
Similar cell maintenance methods
Similar methods for expression of genetic information
Similar processes of energy metabolism
Similar methods for molecular transport and cell signaling
Similar processes for cell development and structure
how is genetic information expressed?
the way you look, walk, eye color, function etc is determined by genes
ow a gene shows up in the persona, how the gene manifests itself on the person
gene expression
expression of the gene that makes you function how you are
phenotype
how cells communicate with each other
cell signaling
how do cells help us understand why something went ary?
because at the cellular level, life is remarkably similar
the transfer of information from one cell to another
cell signaling
how do cells signal eachother?
by direct contact with eachother
by release of substance (hormone or NT) from one cell that is taken up by another cell
why do we need cell signlaing?
important for cells to grow and work normally
How do cells interact
cell signaling
junction bw two cells
synapse
how do receptors on a receiving cel l work
shape of it and NT have to match, if it doesnt meat it, the signaling will not happen and whatever it is signaling is the changing in the cell and therefore will not happen
dynamic and active component of cells
It prevents the free flow of molecules in and out of the cell
It controls the exchange of materials between the external environment and the cell
plasma membrane
compartment with a watery interior that is separated from the external environment by a surface membrane (or wall)
plasma membrame
what is the plasma membrane composed of
a bilayer (2 layers) of phospholipid molecules
what is a phospholipid
A lipid containing a phosphate group in its molecule, e.g., lecithin
describe the structure of a phospholipid
consists of two hydrophobic fatty acid “tails” and a hydrophilic “head” consisting of a phosphate group
what is hydrophobic
water hating
what is hydrophilic
water loving
which part of the plasma membrane is hydrophobic?
tails
which part of the plasma membrane is hydrophilic
head
How do the two phospholipid layers orient
hydrophilic heads face toward the outer and inner surfaces of the plasma membrane
hydrophobic tails are buried within the interior of the membrane
which part of the bilayer is exposed to the water
hydrophilic heads
which part of the bilayer is the plasma membrane
hydrophobic core
what are phospholipid membranes impermeable to
water (because they are water hateing)
all ions
all hydrophilic small molecules (how they control egressing and ingressing)
what do proteins in the membrane do?
some allow specific ions and small molecules to cross through
others serve to attach cells to surrounding cells
others give the cell its shape or allow its shape to change
why are proteins different shapes in the membrane/
different shapes are for different functions - they allow different ions to get through
what gives cells their molecular identity?
molecules on the plasma membrane
what are molecules cell properties important for
blood type
determination of compatibility in organ transplants
what does the plasma membrane enclose
cytoplasm and organelles
complex mixture of molecules and structural components
cytoplasm
bilayer, made of phospholipid with hydrophobic and philic, multiple protein chains on it and these are responsible for given the cell the identity and controls what goes in and out of the cells (ions and molecules, etc.)
plasma membrane
gives the form and shape to the cells
cytoskeleton
system of microfilaments and microtubules that provide each cell strength and rigidity, helping each cell to maintain it’s characteristic shape
cytoskeleton
helps anchor cellular structures and is important for organizing the cell
cytoskeleton
cell motility is facilitated by
microfilaments
are fine, thread-like protein fibers,
plays a role in cell motility & contractility.
microfilament
straight, hollow cylinders found throughout the cytoplasm of all eukaryotic cells
functions, ranging from transport to structural support.
microtubules
Define the organelles
Control their ionic composition so that it is different
organelles
Each has a unique set of proteins that enables it to carry out its function
organelle
specialized structures within the cytoplasm
organelles
Network of membranes that export protein from cells
ER
associated with ribosomes
it functions in the synthesis and processing of proteins
Rough ER
Lacks ribosomes
if functions in lipid synthesis (fat)
smooth ER
synthesize and process proteins
Ribosomes
factories that make your proteins
rough ER
makes lipids
smooth ER
made up of RNA and protein
ribosomes
serves as the primary site of biological protein synthesis
ribosomes
link amino acids together in the order specified by messenger RNA (mRNA) molecules
ribosomes
Flattened membrane sacs that receive proteins from the ER
Proteins are further processed here before being forwarded to their final destination
golgi
Membrane-enclosed sacs that contain digestive enzymes
They break down or recycle worn-out and obsolete cells parts
lysosomes
Largest organelle surrounded by 2 phospholipid bilayer membranes
mitochondria
Energy source of cells that produce most of the adenosine triphosphate (ATP) in eukaryotic cells
mitochondria
what is ATP
energy source that is used to drive most energy-requiring cellular processes
what were mitochondria originally
believed to originate as bacteria that took up residence in eukaryotic cells and over time became welcome collaborators
genetic mutations to antibiotics form where
mitochondria
still contain small genomes that encode essential proteins revealing their bacterial origins
mitochondria
cell organelle involved in energy transformation
mitochondria
contains our DNA
nucleus
Largest, most prominent of the membrane-bounded organelles which characterize eukaryotic cells
nucleus
Responsible for growth and reproduction of the cell
nucleus
Enclosed with a double membrane that allows direct communication between the nucleus and cytoplasm
nucleus
dense regions in the nucleus that synthesize ribosomes
nucleoli
Dark strands and clumps of chromatin (chromosomes) are seen throughout here
nucleus
Contains the cell’s genetic information (DNA) organized into genes that determines the shape, structure, and range of functions carried out by the cell
nucleus
where is genetic information contained?
chromatin that turns into chromosomes in the nucleus
complex of DNA and proteins that make up a chromosome is called
chromatin
Chromatin are organized into
chromosomes
rod-shaped microscopic structures carrying the genes that carry genetic information transmitted from generation to generation
chromosomes
As the cell prepares to divide, the chromatin condenses and coils to form _______
chromosomes
where do genes lie
on chromosomes
How do individual chromosomes take the form of two chromatids?
individual chromosomes connect at the centromere to create the X formation
consists of a single, double-stranded DNA molecule
chromosomes
consists of two DNA strands joined together by their centromere
chromatid
appears as a constricted region of a chromosome and plays a key role in helping the cell divide up its DNA during division
Specifically, it is the region where the cell’s spindle fibers attach.
centromere
short arm of chromosomes
p arm
long arm of chromosomes
q arm
explain the 46 chromosomes in humans
22 pairs of autosomes
one pair (XX XY) are sex chromosomes
what would you see on chromosome for down syndrome?
extra chromosomes of 21
where chromatids join
centromere
Number of sets of chromosomes in a biological cell
ploidy
condition in which each chromosome is represented twice as a member of a homologous pair, one set from each parent
diploid
humans are always _____
diploid
One full set of chromosomes occurring in a mature germ cell or half the number of chromosomes (23) found in a normal somatic cell (22X or 22Y)
haploid
general appearance of somatic chromosomes
karyotype
identical
homologous
chromosome disorders are diff than single gene mutations
true
one gene on a chromosome that has gone ary, genetic mutation
single
an extra or a lack of chromosome, most are not compatible with life because you have taken a whole bunch of genes
chromosome mutation
how the gene will manifest, how you will look, function, behave, etc.
gene expression
Describes alleles present in a gene
genotype
genetic composition of an individual, i.e., the fundamental characteristic of an organism in terms of hereditary factors
genotype
Describes the expression of an allele combination present in a gene
phenotype
The manifest characteristics of an organism collectively, i.e., traits that result from both its hereditary and its environment – nature and nurture
phenotype
