Brief Overview of Human Cell Biology Flashcards
Congenital
obtained during pregnancy
Genetic
inherited from your parents
- can be born or develop later in life
Acquired
something that you get later in life
- not caused by genetics
Why should we study cell biology in a genetic course in audiology?
if something is wrong with the body it starts in the cell
- when things go wrong its at the cellular level
what controls the shape, size, and function of cells
Genes
The two main cell types
Prokaryotic & Eukaryotic
Prokaryotic cells
not human
-no membrane bound nucleus or organelles
-most are bacteria
- found in a coiled loop (chromosome) floating in cytoplasm
Eukaryotic cells
human
-nucleus contains DNA
Somatic cells
everything but your sex cells
cannot build new life
Germ cells
egg and sperm
- cells that can build a new life
- organisms develop from here
What are cells formed from
molecules
Cell signaling
is the transfer of information from one cell to another
- this is important for cells to grow
What happens to cells that lose the ability to respond to signals from other cells
they may become cancer cells or die
Plasma membrane
separates the interior of the cell from the outside
- dynamic & active
- controls what goes in & out of the cell
- prevents free flow of molecules
- bilayer of phospholipid molecules
What is the plasma membrane made up of?
- composed of a bilayer of phospholipid molecules
made of of lipids and fats
Phospholipid
a lipid containing a phosphate
how is genetic information expressed?
the way you look, walk, eye color, function etc is determined by genes
organelles
specialized structures within the cytoplasm & include:
- Endoplasmic reticulum (ER)
Where are organelles NOT found?
in red blood cells
rough ER
associated with ribosomes
- function is the synthesis & processing of proteins
smooth ER
lacks in ribosomes
- function is lipid synthesis
describe the two layer structure of a phospholipid
consist 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
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
What encloses the cytoplasm
plasma membrane
What is within the cytoplasm
The cytoskeleton
- microfilaments & microtubles provide cell strength & rigidity (maintaining shape)
- anchors cellular structures (organizing cell)
- plays a key role in motility
Microfilamnets
fine & thread like
- 3-6 nm
- Actin (contraction) & myosin (relaxation) allowing skeletal muscles to move
Microtubles
straight hollow cylinders
- NOT founf in prokaryotic cells
Ribosomes
made of RNA & protien
- found in both endoplasmic reticulum & free in the cytoplasm
Ribosome function
- serves as the primary site of biological protien synthesis
- the link amino acids together in the order specified by messenger RNA(mRNA) molecules
What are building blocks of protein?
amino acids
Golgi apparatus
- flattened membrane sacs that contain digestive enzymes
- proteins processed here before moving to final destination
Lysosomes
- membrane enclosed sacs containing digestive enzymes
Lysosome function
break down or recycle worn out cells
- this is how a cell rejuvenates and re corrects itself
Mitochondria
- Largest organelle surrounded by 2 phospholipid bilayer membranes
- Energy source of cells that produce most of the adenosine triphosphate (ATP) in eukaryotic cells
what is ATP
energy source that is used to drive most energy-requiring cellular processes
Nucleus
largest and most prominent of the organelles
-responsible for growth and reproduction of the cell
-contains DNA (organized to determine shape, structure, & function
What is within the nucleus
nucleoli
- dense regions that synthesize ribsomes
chromatin
complex of DNA and proteins that make up a chromosome
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
P arm
short arm of chromosome
Q arm
Long arm of chromosome
what is it called when two chromatids are joined by a centromere
sister chromatids
diploid
2 sets of chromosomes
- one from each parent
Haploid
- half
one set of chromosome
Karyotype
- The general appearance of somatic chromosomes
- what they look like
Genotype
- genetic makeup
Phenotype
expression of genes
- eye color, hair color, etc…
