Quiz 1 Flashcards
What are synarthrotic joints found in teeth called
Gomphoses
Epimysium surrounds what part of a muscle?
Entire muscle
Endomysium surrounds what part of a muscle?
Individual fibers
The motor unit consists of what elements?
motor neuron, muscle cell
What organelle in muscle cell stores Ca2+
Sarcoplasmic reticulum
When calcium is released from the SR, what transport protein do they move thru?
Ryanodine receptors (RyRs)
Calcium is pumped back into the SR via what pump? Is this an active of passive process?
SERCA, active
During muscle contraction, what components of the cell actually shorten?
H zone and I band
I band consists of what?
Actin fibers
A band consists of what?
Myosin fibers
What proteins anchor the myosin to the Z disc?
Titins
Sarcomere is defined by what boundaries?
Z disc to Z disc
Calcium will bind to what protein in order to allow myosin to bind to actin?
Troponin
In a relaxed muscle cell, what protein is blocking the binding site of actin/myosin
Tropomyosin
After myosin and actin binding, what needs to happen for the power stroke to begin?
ATP is hydrolized releasing an inorganic phosophate
During the power stroke, how far do the filaments slide?
about 10 nm
After the muscle filaments slide in contraction, what is needed for the muscle to relax?
ATP to bind to myosin
What is the neurotransmitter at the neuromuscular junction?
Acetylcholine
Action potential infiltrates the muscle via what?
Transverse tubules
Intercalated discs are present in what muscle?
Cardiac
Intercalated discs link cells together via what?
Gap jcts, Desmosomes
T/F: Smooth muscle contains troponin?
False
T/F: When calcium levels in smooth muscle decrease, the contracted muscle always relaxes
False, cross bridges can remain attached providing sustained contractions with little energy cost
Name the four types of tissue
Epithelial, Connective, Muscle, Nervous
Blood is considered what type of tissue
Connective
Name 4 ways we study and examine tissue
Whole mounts, squash slides, smear slides, section slides
3 functions of epithelial tissue are what?
Protective barrier, Absorption, secretion
T/F: Epithelial tissue is highly vascularized
False, typically avascular and relies on diffusion of blood from CT
The apical pole of epithelium faces what?
lumen
The basal pole of epithelium faces what?
CT
The basement membrane is…
a thin sheet of ECM attaching epithelium to CT via hemidesmosomes
The basement membrane is composed of what 3 zones
lamina lucida
lamina densa
lamina fibroreticularis
The lamina lucida is composed of what?
laminin, entactin, integrins
The lamina densa is composed of what?
Collagen IV
Where would you likely find simple squamos epi tissue?
lining blood and lymph vessles
where would you most likely find stratified squamos epi tissue?
anything that might encounter abrasive forces regularly, ex. skin, attached gingiva, vagina
Simple columnar cells would most likely be found where?
mucus secreting and absorptive surfaces, ex. GI tract
Microfilaments are composed of what and have what function?
Actin
structural, filopodia, cell shape
Intermediate filaments are composed of what?
Vimentin, cytokeratin
Anchors and structural support only - non contractile!
Microtubules are composed of what and have what function?
Tubulin
Monorail system, cilia, flagella
Tight junctions include what proteins?
Claudin, occludin, JAM
Adhesive junctions - zonula adherins - contain what proteins and where are they located in reference to the cell?
Catenins - inside the cell
Cadherins - outside the cell
Cadherins are dependent on what?
calcium
Desmosomes attach to what inside the cell?
Intermediate filaments
Adhesive Junctions - zonula adherins - attach to what inside the cell?
Microfilaments - Actin
Hemidesmosomes attach to what inside the cell? To what outside the cell?
Inside - intermediate filaments
Outside - basal lamina of basement membrane
Gap junctions are composed of a unit made of multiple subunits, what are these and how many are needed to maek one?
6 connexins = 1 connexon
T/F: Nucleic acids, proteins, and carbs can pass thru gap jcts
False, these molecules are too large
Gap jcts are best for what purpose?
Propagation of electrical signals
During epithelial turnover and maintenance, pluripotent progenitor cells complete mitosis where?
Basal lamina
Connective tissue consists of what components?
cells, ECM fibers, ECM ground substance
Functions of CT include?
Mechanical/structural support, storage of interstitial flui, tissue repair, defense and immune protection
Cells always found in CT are what?
fibroblasts, adipocytes, macrophages, mast cells
Fibroblasts have what function?
ECM production and tissue repair
Collagen is a major product of cell from what lineage?
mesenchyme
Most abundant protein in body?
collagen
What is an example of a disease associated with collagen deficiency/malfunction?
Scurvy - vitamin C is a coenzyme needed for collagen fabrication and scurvy is a result of Vit C deficiency
Elastin is a product of what cell
Fibroblast
Elastin fibers accumulate onto a protein matrix composed of what proteins?
Fibrillin 1 and 2
What is a disease/disorder associated with compromised elastin?
Marfans syndrome - fibrillin 1 mutation
What are 4 functions of adipocytes?
Store energy
Insulate
Provide cushion for organs
Synthesize hormones
CT Ground substance is composed of mainly what two elements?
proteoglycans and glycoproteins
CT Ground substance has what main function
sequesters fluid to provide compressive strength
“keeps squidgy things squidgy”
proteoglycans are a product of what cell?>
fibroblasts
proteoglycans are composed how?
protein backbone with glycosoaminoglycan chains (GAGs)
What is an important function of proteoglycans?
can hold onto growth factors for later use
ECM is digested by what cells?
fibroblasts and matrix metalloproteins (MMPs)
Which CT contains the most cells within?
loose CT
Humans require what source of energy?
chemical
Identify the false descrptions:
Prokaryotic cells contain: No cell wall membrane bound organelles Cytoplasmic DNA Cytoskeleton 80s ribsomes replicate via binary fission diversity comes from meiosis/recombo
NO membrane bound organelles
NO cytoskelton
70 s ribosomes
diversity comes from mutations
Typically most pathogenic bacteria are in what class?
Gram negative, contain LPS
The most important function of cellular membranes is what?
segregation, critical for biochemical rxns
The majority of cell membrane components is found where?
RER
Some characteristics of lipid rafts are what?
cholesterol and sphingolipid rich
limit fluidity
anchor for other organelles
signal transduction and endocytosis
Name 5 types of endocytosis
Phagocytosis macropinocytosis clathrin dependent endocytosis caveolin dependent endocytosis clathrin and caveolin independent endocytosis
What types of endocytosis are dependent on lipid rafts?
caveolin dependent, clathrin and caveolin independent endocytosis
Functions of endocytosis?
remodel plasma membrane
alter ECM environment
provide nutrients
regulate and amplify signal transduction
Clathrin dependent endocytosis is dependent on what protein?
Dynamin
An early endosome can turn into what 2 organelles?
late endosome
recycling endosome
microtubule motors include what?
Kinesin, Dynein
Kinesins travel in what direction
anterograde (away from nucleus)
Dyneins travel in what direction
retrograde (toward nucleus)
T/F: Glycolysis occurs in mitochondria
False, occurs in cytoplasm
Where does citric acid cycle occur>
matrix of mito
Where does ETC occur?
Inner membrane of mito
RNA polymerase reads in what direction on what DNA strand?
3 - 5
template strand
RNA leaves the nucleus via what?
Nuclear pore complex
Human ribosomes are composed of what two subunits?
60 s lg unit
40 s sm unit
Proteins that remain in cytosol are typically made where?
Cytosol
Proteins bound for the plasma membrane are typically made where?
RER
chromatin is dispersed in the nucleus during what stage of the cell cycle?
G0 phase, cell cycle arrest phase
Gap phase 1 (G1) what happens>
cellular contents duplicated (NOT chromosomes)
What phase are chromosomes duplicated?
S (Synthesis) phase
What happens during Gap 2 phase?
chromosomes cohere and proper duplication is checked
Mitosis produces what kind of cells?
diploid
Meiosis produces what kind of cells?
haploid
What 3 units make up a nucleotide?
pentose ring
1-3 phosphate groups
purine/pyrimidine base
What are three main functions of nucleic acids?
Information transfer
Energy transfer
Signal transduction
Primary structure of DNA and RNA consists of what?
sequences of nucleotides
secondary structure of DNA and RNA consists of what>
interactions b/w bases. DNA has a double helix, RNA folds loops, hairpins.
Tertiary structure of dna and rna consists of what
structural dimensions of atoms; #bps/turn, length of helix turn, handedness
quaternary structure of dna consists of what
interaction with other molecules, histones, ribosomes, etc. DNA interacts with histone proteins to make chromatin
T/F: Nucleic acids can act as energy carriers, coenzymes, and signalling molecules
True
What are 5 functions of lipids/fatty acids
energy storage membranes constituents carry info and signal vitamins, cofactors, colorants surfactants
Name three common linker molecules
glycerol, sphingosine, glycerophosphate
name 3 major membrane lipids
phospholipids, sphingolipids, glycolipids
How can triglycerides be converted into chemical energy?
by undergoing beta oxidation then entering krebbs cycle as acteyl CoA
Glycolipids are mostly for what function of the cell?
cellular ID,
anchoring proteins to membranes
Sterols are what and are located where?
membrane fatty acids
What are functions of sterols?
increase membrane fluidity
reduce permeability
lipid raft components
necessary for endocytosis
name three inflammatory lipids
prostaglandins
thromboxanes
leukotrienes
What enzymes produce inflammatory lipids?
COX 1/2