Lectures 3 and 4 Flashcards
What are the two main factors that can cause hearing loss to occur?
Environmental factors and genetic
What is an example of an environmental factor that can cause hearing loss?
Viral infection that is acquired during pregnancy
CMV, meningitis
Why are hearing losses genetic?
The development of the auditory-vestibular system depends on sequential activation of multiple genes
Problems with one gene can cause hearing loss
Can hearing loss be both genetic and environmental?
Yes
Could have a genetic mutation that makes you susceptible to hearing loss that only presents itself after taking a certain type of medication
Why is understanding genetic causes of hearing loss important?
It could allow doctors to inform families about their chances of having children with hearing loss
It could also predict if their hearing loss is going to get worse
What does syndromic mean?
They don’t just have hearing loss, they also have problems with other organ systems
Is it common for children to have genetic deafness/hearing loss even if neither of one of their parents are affected?
Yes
This is why genetic testing for hearing loss is important
What is a cell?
The basic unit of structure and function in all organisms
What are genes?
They control the shape, size, and function of cells
What are the two main cell types?
Prokaryotic and eukaryotic
What are prokaryotic cells?
Cells with a plasma membrane but do not have a membrane-bound nucleus or other membrane bound organelles
DNA found floating in the cytoplasm
Unicellular
What are eukaryotic cells?
Human cells
Plasma membrane and nuclear membrane along with other organelles
Nucleus has DNA
What is a nuclear membrane?
The cell wall or covering around the nucleus
What are somatic cells?
Body cells
Everything but sex cells
Cells that differentiate into tissues and organs in the body
What are germ cells?
Egg and sperm cells
Sex cells
Cells from which a new organism can develop
T/F: Your cells work together
True
Can different issues in the body (cardiovascular) affect the ears?
Yes
Everything is interrelated
How are all cells similar?
They all have the same molecular building blocks
They all have similar methods for storage
They all have similar cell maintenance methods
They all have similar methods for expression of genetic information
They all have similar processes of energy metabolism
They all have similar methods for molecular transport and cell signaling
They all have similar processes for cell development and structure
What is cell signaling?
How cells communicate with each other and their environments
What are the ways that cells can signal to each other?
They can do so through direct contact or by the release of substances (hormones or NT)
What is MS?
When myelin degenerated and cell signaling is affected
What is a plasma membrane?
The cell wall
Dynamic and active component of the cell
What does the plasma membrane do?
It prevents the free flow of molecules in and out of the cell
T/F: Eukaryotic cells also have extensive internal membranes that further subdivide the cell into compartments that contain the organelles
True
What is the plasma membrane comprised of?
A bilayer of phospholipid molecules
Two hydrophobic fatty acid tails and a hydrophilic head
What does the phosphate group form on in the bilayer?
The water loving head
What is a phospholipid?
A lipid containing a phosphate group
Smaller amounts of other lipids such as cholesterol are inserted into the phospholipid framework
What are phospholipid membrane impermeable to?
Water
All ions
All hydrophilic small molecules
Does the plasma membrane also have proteins?
Yes
These proteins allow specific ions and small molecules to cross through
Other give the cell its shape or allow the shape to change
T/F: the molecules on the plasma membrane provide cells with their molecular identity
Yes
The type and number of molecules are genetically controlled and responsible for what important cell properties?
Blood types
Determination of compatibility in organ transplants
T/F: Some genetic disorders (cystic fibrosis) are associated with plasma membrane anomalies
True
What is cytoplasm?
A complex mixture of molecules and structural components
What is a cytoskeleton?
Within cytoplasm
A system a microfilaments and microtubules that provide the cell with strength and rigidity
Helps anchor cellular structures
Helps organize cell
Key role in cell motility
Are microtubules and microfilaments protein?
Yes
What are microfilaments mostly comprised of?
Actin (for contraction)
Tiny hair-like
Do eukaryotic or prokaryotic cells have extensive internal membranes that enclose specific compartments and make to organelles?
Eukaryotic
What do internal membranes do?
Define the organelles
Control their ionic composition so that it is different from the cytoplasm and other organelles
Does each organelle have a unique set of proteins that enables it to carry out its function?
Yes
Is everything that is functional in the body made up of proteins?
Yes
What is the endoplasmic reticulum?
An organelle
Network of membranes that export protein from cells
What are the two types of endoplasmic reticulum?
Smooth - lacks ribosomes, lipid synthesis (function)
Rough - ribosomes, synthesize and process proteins (function)
What are ribosomes?
Small particles found both in the endoplasmic reticulum and free in the cytoplasm
Made up of (ribonucleic acid) RNA and protein
Ribosomes link amino acids together in the order specified by messenger RNA (mRNA) molecules
What are amino acids?
The building blocks of protein
What is the golgi apparatus?
Flattened membrane sacs that receive proteins from the ER
Proteins are further processed here before being forwarded to their final destination
What are lysosomes?
Membrane-enclosed sacs that contain digestive enzymes
They break down or recycle worn-out and obsolete cells parts
Mitochondria
What is the nucleus?
The largest, most prominent of the organelles
Responsible for growth and reproduction of the cell
Enclosed with a double membrane that allows direct communication between the nucleus and cytoplasm
Contains the cell’s genetic information (DNA) organized into genes that determines the shape, structure, and range of functions carried out by the cell
T/F: There are dense regions within the nucleus called nucleoli that synthesize ribosomes
True
T/F: Darks strands and clumps of chromatin (chromosomes) are seen throughout the nucleus
True
What is chromatin?
The complex of DNA and proteins that make up a chromosome
Chromatin is organized into chromosomes
What are chromosomes?
Rod-shaped microscopic structures carrying the genes that carry genetic information transmitted from generation to generation
As the cell prepares to divide, the chromatin condenses and coils to form chromosomes
How are chromosomes formed?
They take the form of two chromatids connected at the centromere to create an “X” shape
Two chromatids joined by the centromere are called sister chromatids
How many pairs of chromosomes are in humans?
23 pairs (46 chromosomes)
What are the short and long arms of the chromosome called?
The short arm is p and the long arm is q
How many pairs of chromosomes are autosomes?
22
1 pair is sex chromosomes