Exam 1: General Information Flashcards
Cells with the same morphology for function form???
Tissues
Anatomically discreet collections of tissues. they perform certain functions
Organs
Cells that make up a functional element of an organ
Parenchyma
structural framework of an organ or background tissue.
Stroma
Contains modified cells responsible for intercelluar communication
Nervous tissue
What happens to unfixed tissues??
The autolyze and dentature
What can be used to fix tissues in tissue preparation?
fix in FORMALIN, (37% formaldehyde). This causes cross-linking for proteins and preserve the tissue.
What are most common types of stains??
Hematoxylin- blue basic dye. This stains acids and is basophilic (blue/purple).
Eosin which is a red pink acidic dye which stains bases (esinophillic means red/pink)
What is another name for cell membrane
plasmalemma. This is semi-permable membrane (SPM)
What does amphoteric mean?
Able to reaction with both acids and bases.
What does Amphipathic mean?
Something that has both hydrophobic and hyrdophillic parts.
Describe the hydrophilic portion of the cell membrane
Contains + charged N Groups and Charged phosphate groups.
Describe the hydropobic portion of the cell membrane
This portion contains two long FA’s chains. These are covalently linked to glycerol.
Tri-laminar appearance of Cell membrane on EM
2 electron dense layers (phopholipid heads)
1 electron lucent layer of the FA tails
Describe changes in the fluidity of the cell membrane
Fluidity increases when the temperature increases and also increases with the decrease in the saturation of FA’s.
How does cholesterol function in the cell membrane
It decreases fluidity and stiffens the membrane.
What is the ratio of cholesterol to phopholipds
about 1:1
Synonyms for surface proteins
Peripheral, and extrinsic
What is an intrinsic protein?
is within the cell membrane also know as integral protein
Synonym for transmembrane protein?
transmural
Cell membrane channels
Allow the passage of water-soluble molecules via diffusion
What is a transducer in the cell membrane?
It initiates enzymatic rxns following the binding of ligand molecules
Enzymes
component of ion pumps and digestive action
What is a gyloccalyx ?
What are the two types?
What are their functions?
- cell membrane proteins or lipids conjugate with short polysac. chains containing glucose molecules.
- form glycoproteins and glycolipids
- protects the surface of cell memebrane, cell recogn. and importance in exchange of material inside and out of cell.
What is another name for bulk diffusion??
vesicular
What can increase the amount of passive and facilitated diffusion across the cell?
surface area via microvilli
where does active transport take place??
“Dynamic pore sites” usually transmmebrane proteins
Two types of Bulk (vesicular) Transport
Endocytosis= phago- and pino-
In receptor mediated transport, what is another name for the membrane receptor??
Clathrins or clatherin coated pit.
What are the two types of categories of organisms??
Prokaryotes: monera and cyannobacteria
Eukaryotes: single celled protists (protazo and metazoans)
Know the difference between Ekaryotes and Prokaryotes:
Prokaryotes:
- lack -
nucleus with envelope, membrane bound organelles, histones, lack axoneme
- circular DNA
Eukaryotes:
have nuclues, and organelles, complexed histones with dna,
What is the composition of protoplasm and what is it?
70-85% water; electrolytes, protiens, lipids, and carbohydrates
What percent of the nuclues does the genome take up?
20%
Chromatin
DNA and nucleoprotiens
Alleles
different forms of the same gene.
Diploid vs. Haploid
diploid in humans =46
haploid of sex cells =23
Karyotyping definition
sorting fo chromosomes pairs by shape and size
What is Heterochromatin?
electron dense, dark staining, inactive DNA and nucleoproteins
- FEMALES HAVE BARR BODY
- show degenerat X chromosome; only one pair active other degenreates
What is euchromatin?
disperesed, active DNA in transcription. (RNA Synthesis)
- cells with active transcription will have prominent nucleolus
What happens when Heterochromatin becomes Euchromatin?
Active portions of the chromosomes unravel to become visible as “lamp brush chromosomes”
What is a histone and how does it function?
The most common nucleoprotein.
Assists in DNA folding–> chromatin organization into chromosomes.
What is a nucleosome?
segments of DNA wrap around several histones to regulate DNA Activity.
NON-Histones
not histones, but are nucleoproteins which can help regulate gene activity.
What is the function of the nuckear envelope??
It separates the nucleoplasm from the cytoplasm
What are the layers of the nuclear envelop?
Inner Layer
Perinuclear Cisterna
Outer layer
What is unique about the inner nuclear membrane?
It is associated with a network of lamina called the nuclear lamina
What is unique about the Out nuclear membrane??
The outer surface is studded with robosomes. This layer is continuous with the ER.
What connects the inner and out nuclear membranes?
Nuclear pore complex.
This is a channel that is about 70-80 nm in diameter, and is surrounded with rings of proteins called, Nucleoporins.
What is a nucleoporin??
A ring of proteins that make up the edges of the nuclear pore complex in the nuclear pore complex.
What is the function of the nuclear envelop? AKA that nuclear membrane??
This regulates the exchange of macromolecules between the cyotplasm and the nuclearplasm.
How are ribosomes measured??
- Svedberg units
- Ribosomes are two subunits a 40s and a 60s
- They are proteinaceous and contain rRNA.
Where can you find Ribosomes
In the cytoplasm
On the ER
On the Nuclear Envelope!
What is a polysome or polyribosome?
It is a grouping of ribosomes.
What cells lack mitochondria?
RBC and Keratincoytes
What are some characteristics of the mitochondria outer membrane??
it is permable and and contains pore forming proteins called porins.
What are some characteristics of the mitochondria inner membrane?
Pleaded to form cristae.
On these cristae there are elementary paticles that contain enzymes for oxidative phos.
What fills the inner matrix?
There is an amorphous matrix material.
there are also dense granules that function to store CA.
Describes the genetic characteristic of Mitochondria
the DNA is maternal, it is circular and the mitochondria reproduce through binary fission,
Where does cell respiration begin?
In the cytosol with glycolysis.
Is glycolysis anaerobic or aerobic?
It is an anaerobic production.
What is produced form glycolysis?
Pyruvic acid which enters into the mitochondria through diffusion.
Where does the Krebs cycle take place.
In the mitochondrial matrix.
What is produced from the Krebs cycle?
CO2, H20 and ATP
What functions to cytochromes have in in the ATP cycle?
Cytochromes are a part of oxidative phos. and are located in the Electron Tranport Chain
Where are cytochromes located??
They are enzymes located on the inner membrane of the cristae.
What is the function of Smooth ER?
lipid synthesis
transport proteins from ER to golgi
membrane formation and recycling
It also functions in cholesterol and steroid hormone production, and is the site of detoxification and conjugation of drugs and toxins
The coated vesicles of the smooth ER are used for??
they are used for transport between the smooth Er and the golgi and the golgi to the cell surface.
What is the function of the golgi
The golgi function in post-translation modification.
This can include sulfation, phosphorylation, and gylcosylation
Describe the cis face of the golgi
it is the forming face that recieve the transfer vesicles which are coated. This face is convex.
Describe the trans face.
It is concave, maturing face, and the proteins are packaged into clathrin coated vesicles for secretion.
What are condensing vacuoles and how do they relate to the golgi?
They first bud off the trans face of the golgi . They are are precurosr for secretory vesciles. HONESTLY THEY MIGHT BE THE SAME THING I AM A BIT CONFUSED.
Secretory Granules are used for what within the cell?
They are used for long term storage of proteins with the cell that come from the golgi. This is the long term storage form.
Membrane trafficking, What the heck is it?
It is the movement of intercellular membrane forming with the outer cell membrane, and therefore can be recycled back to the golgi. Think of the movement of exocytosis.
What is an example of a hydrolytic enzyme within the lysosome?
acid phosphotase.
What is the inactive form of a lysosome?
It is the newly formed version from the rER and golgi and is CALLED 1’ lysosomes
When do lysosomes become active
When they form with phagosomes and become 2’ lysosomes AKA phagolysosomes.
What is the function of a 3’ lysosome?
It is the product of hydrolytic breakdown. This lysosome is also know as a residual body?
can remain in the cell or be excreted.
What are some examples of residual bodies aka 3’ lysosomes?
common examples are lipofuscin pigment granules in the neurons.
How do lysosomes function in cell death (apoptosis or autophagy)?
they degrade the cell organelles and cells with finite lifespans.
What is an endosome?
endocytic vesicle with acid pH in the lumen of the Alimentary canal.
Perioxisomes are similar to Lysosomes in function, but what enzymes do they contain?
oxidative enzymes: oxidases
catalase
peroxidase
How do peroxisomes function?
They use free radicals, hydrogen peroxide and enzymes to oxidize toxic metabolites.
What are cell inclusions?
non-living components of the cell.
example: neutral fat droplets, lipids, glycogen, secretory and pigment granules.
What do we need to know about Viral inclusions
can be intracytoplasmic or intranuclear.
MAYBE NOT IMPORTANT< BUT IDK
What is a black, brown granular pigment that is produced by melanocytes and is transported to other cells.
Melanin
What is a gold-brown granule.
Lipofusin: this is frequently found iin neurons: sometimes called the old age pigment
What are some functions of the cytoskeleton?
structural support, intracellular movement and transport of substances, Cell locomotion, and Muscle contraction
What are some examples of cell locomotion?
amoeboid movement, embryonic development, cilia and flagella.
What are the three main elements of the cytoskeleton?
microfilaments, intermediate filaments, and microtubules.
What is an important role of microfilaments?
important in maintaining cell shape, faciliatate shape changes during movement.
Wound contraction during healing and muscle contraction.
What are some characteristics of actin?
thin filament,
comprised of smaller g-actin subunits,
What is G actin?
a small globular protein monomer that polymerizes to form protofilaments.
How do protofilaments work to form Actin?
several g-actin monomers form protofilaments. Two protfilaments twist to form a double helix (f-actin) F actin then combine to form larger actin filaments.
Where is actin located within the cell?
beneath the plasma membrane.
Here actin links with filamin. This linkage forms the cell cortex aka the terminal web. This terminal web prevents the cell deformation.
Where is actin also found in the cell?
Microvilli and stereocillia.
Is myosin a thick or thin filament?
thicccck
What is myosin also classified as?
motor protein, dynein, and kinesin
Describe a myosin molecule.
long rod shaped with globular heads
What do myosin heads form?
cross bridges between adjacent filaments.
How do CA and ATp interact with myosin?
They are required for movements of filaments for the muscle contraction.
List the elements of the cytoskeleton from large to small.
microtubule, intermediate filaments, and microfilaments.
Facts of intermediate filaments
- typically form larger filaments that bind with intracellular structures
- Useful in immunohistochemistry and tumor ID.
Cyto(keratin)
seen in all epithelial cells. In the epidermis of the skin it forms tonofibrils.
What is a tonofibril?
formation fo keratin or cytokeratin in the epidermis.
Vimentin
this is an intermediate filament that is located in the mesodermal cells of the mesenchymal origin.
(includes endothelial cells, muscle and neuroectodermal cells.
desmin
this is an intermediate filament that is unique to muscle cells. this has its origins in the mesoderm.
neurofilament proteins
these are intermediate filaments that are present in nerve cells
GFAP (glial fibrillary acidic protein)
intermediate filament found in glial (support) cells of the nervous system)
What is an example of a glial fibrillary acidic protein.
astrocytes
Lamin
intermediate filament that forms layer on the inside of nuclear membrane.
What are the two types of globular protein subunits that make up microtubules?
Alpha tubulin and Beta tubulin.
How are microtubules formed?
The beta and alpha subunits polymerize to form hollow tubes. These tubes are readily assembled and disassembled.
What are some functions of microtubules?
cell movement, maintenance of cell shape and intracellular transport of substances.
how does movement occur with microtubules?
tubulin subunits are either added or removed.
How do dynein and kynesin function in organelle movement?
these are motor proteins that attach mircotubules to organelles; which allows for movement in cytoplasm.
What is a classic example of mictotubules?
cell spindle during cell division.
What drugs inhibit polymerization of microtubules and what is the end result?
Inhibitory drugs include:
- Colchicine
- vincristine
- vinblastin
These drugs result in the inhibition of cell division.
Where are microtubules found?
cillia and flagella
centrioles
basal bodies of cillia
mitotic spindles
What is an axoneme?
it is a combination of 9 pairs of microtubules (peripheral doublets) that contain dynein arms that are arranged in a circle with a central doublet in the middle.
What is the general structure of the doublet?
9+2 structure
What connects the central doublet to the peripheral doublets?
Radial spokes
What connects the peripheral doublets together?
nexin
How are axonemes formed in cillia?
they grow from the BASAL BODY which is derived from a modified CENTRIOLE.
Where are centrioles located?
it is located in the centrosome region aka the cell center. This “cell center” is located near the nucleus and functions in cell division
What is another name for a pair of centrioles?
diplosomes
Describe the orientation of diplosomes during cell division.
They are oriented at 90 degree angles.
How is the composition of a centrriole?
9 triplets or microtubules that are arranged into a cylinder.
What is a function of a centriole?
It acts as an nucleation center for microtubules.
What controls the movement of chromosomes during cell division.
The addition and removal of tubulin subunits and attachment proteins (dynein and kynesin) to chromatids at the kinetochore aka the centromere.
TAKE THIS TIME TO LOOK BACK AT WHAT DYNEIN AND KYESIN DO AND CONNECT IT TO THIS CARD).
What are the phases of mitosis
Interphase, Prophase, Metaphase, Anaphase, Telophase.
What is interphase?
How can it be divided?
- Interphase is the restin phase between cell divisions.
(This occupies most of the cell life) - It has subphases G1, S, and G2
What is the G1 Phase of interphase? `
- the first gap phase
- This is the longest of the cell stages (lasts hours or days)
- The cell grows, matures, and differentiates.
- the cell experiences hypertrophy (increase in size)
_ it also experiences hyperplasia (increase in cell number)
What is the S phase of interphase?
This is the synthesis stage where DNA is replicated prior to cell division.
- the the beginning of S phase, the chromosome count is 2n and at the end it is 4n.
What happens before there is replication in the S phase? Concerning chromosomes? `
each chromosome has a single chromatid with an attached centromere.
What happens as a result of the synthesis stage concerning chromosomes?
At the end of the S phase each chromosome contains 2 chromatids connected by a centromere.
What else is replicated during the S phase?
The centrioles are replicated AKA two diplosomes.
What happens in the G2 phase of interphase?
This is the 2nd gap phase.
Synthesis of ATP and Tubulin for the mitotic spindle.
M Phase of the Cell Cycle is mitosis.
What are two characteristics of mitosis?
Karyokinesis and then cytokinesis
two new daughter cells.
What is karyokinesis?
nuclear divison
What is cytokinesis?
cytoplasmic divsion
What happens to the appearance of chromosomes in the S and M phases of the cell cycle?
the chromosomes condense and become visible.
What us tge G0 phase? `
outside of the cell cycle.
this means that it does not participate in the cell cycle.
This may be permanent or reversible.
What is the definition oof facultative dividers?
They retain the capacity for division with proper stimulus.
An example of this stimulus is the reserve stem cells.
What does terminally differentiated mean in regards to cell division?
cells lose the capacity to divide.
Examples include: neurons, and cardiac myocytes.
Characteristics of Prophase:
- the chromosomes are visually condensed.
- Microfilaments and microtubules of cytoskeleton disaggregate.
- the centrioles migrate to the ends of the cells. where they form a spindle apparatus with the interpolar microtubules between them. q
What are characteristics of prometaphase?
- This is also known as late prophase.
- the nucleus disappears
- the mitotic spindles attach to the chromosomes at the kinetochore.
What is a key characteristic in metaphase??
the chromosomes line up in the middle of the cell. This can also be called the metaphase plate.
What pulls the chromosomes apart during anaphase?
The centromeres that attach to microtubules are split and allow the microtubules to pull the chromosomes apart. Kinetochore is connected to the centriole via microtubules.
What are key characteristics of telophase??
- the mitotic spindle disaggregates
- The nuclear envelope reassembles and the nucleoi reappear.
- the cleavage furrow appears.
What is the mitotic index?
a tested used to describe the proportion of cells in a tissue in mitosis at any given time.
Done by counting the # of mitotic figures/ HPF
this is normally <1
WHAT IS HPF?
What is happening in Meiosis?
Chromosomal duplication followed by two consecutive cell divisions.
How many rounds of cell division occur in Meiosis??
both phases have a pro, meta, ana, and telophase.
How does meiosis differ from mitosis??
In prophase 1 homologous pairs form tetrads with crossing over (chiasmata formation).
What is the impact of crossing over?
hybrid chromatids that are different from the parent cells.
Between the first phase of meiosis and the second phase what is there?
interkineisis or interphase II there is no replication of DNA in this phase.
How does gametogensis differ between men and women?
Spermagenesis results in three to four viable sperm.
In women there is one functional gamete and 2 to three polar bodies.
When does gametogensis begin in both men and women?
In men: at puberty
in Women: during fetal development?
Describe the stages of oogenesis in women.
Women enter into prophase I during the 5th month of gestation and then they stop.
They remain in prophase I until 12-50 years later.
What is the impact of crossing over?
hybrid chromatids that are different from the parent cells.
What is clonal deletion?
this occurs in the thymus and is the removal of t-cells that react to “self” molecules. If this does not occur then auto-immune diseases can occur.
Apoptosis looks the same in every every cell. Briefly describe the general characteristics of apoptosis.
- pyknosis: the condensation of nuclear chromatin and the shrinkage of the nucleus.
the cell will swell because of the stop in ATP production and the pumps begin to fail. Water accumulates in the cell.
Lysosomes burst and release catalytic enzymes into the cytoplasm. This causes autolysis.
the cytoplasm becomes esionphillic.
When does gametogensis begin in both men and women?
In men: at puberty
in Women: during fetal development.
What can trigger apoptosis?
growth and regression of ovarian follicles and CL
Clonal deletion
What is clonal deletion?
this occurs in the thymus and is the removal of t-cells that react to “self” molecules. If this does not occur then auto-immune diseases can occur.
Apoptosis looks the same in every every cell. Briefly describe the general characteristics of apoptosis.
- pyknosis: the condensation of nuclear chromatin and the shrinkage of the nucleus.
the cell will swell because of the stop in ATP production and the pumps begin to fail. Water accumulates in the cell
What is the caspace cascade?
it is the final pathway in apoptosis. Caspaces are normally inactive enzymes.
What is karyolysis?
Chromatin in the nucleus begins to degenerate.
Karyorhexis, what is it?
the nuclear material begins to fragment and nuclear membrane disintegrates.
What is the remaining nuclear debris sometimes referred to?
apoptotic bodies.
What digests the necrotic cells.
macrophages and neutrophils.
