Organelles Flashcards
Does a prokaryote have a nucleus?
No
What is the diameter of a typical prokaryote cell?
1 um
What is the diameter of a typical eukaryote cell?
10-100 um
Does a prokaryote cell have a cytoskeleton?
No
Does prokaryote have cytoplasmic organelles?
No
Prokaryote cells have ______ ______ DNA
Single Cirulcar
Eukaryote cells have ______ ______ DNA
multiple linear
Walls of prokaryotes are made of?
Carbohydrate (peptidoglycan)
RER is responsible for _____ production
protein
SER is responsible for _____ production
lipid
What gives membranes their shape?
microfilaments
What is the backbone of all membranes?
phospholipid bilayer
How does cholesterol affect a membrane?
It increases the rigidity
Cholesterol has a ______ head
hydrophilic
Glycolipid is a phospholipid with ______ attached sugar chains
covalently
What kind of chains only face the extracellular surface?
Carbohydrate chains
What is another name for integral protein?
Transmembrane protein
What color will gram-negative prokaryotes stain?
Pink
What color will gram-positive prokaryotes stain?
Purple
Explain why some prokaryotes will stain pink and some purple
Gram negative bacteria has to membranes, (outer membrane, then cell wall, then plasma membrane) so the stain can’t get through the wall. Gram positive bacteria only has one plasma membrane (a cell wall on top) so stain binds to carbohydrates in cell wall and it stains purple
What is glycocalyx?
The name of carbohydrates on eukaryotic surface
What cannot cross a cell membrane unless they are transported through channels or transporters?
Anything hydrophilic (can’t cross the hydrophobic part of bilayer)
A vacoule is responsible for?
Water storage
What is responsible for the synthesis of ribosomal RNA?
nucleolus
What is responsible for DNA replication, synthesis of tRNA, mRNA, and some nuclear proteins?
Nucleus
Where does glycolysis, and many reactions in gluconeogenesis take place?
Cytosol
Where does pentose phosphate pathways, activation of a.a., fatty acid synthesis, and nucleotide synthesis take place?
Cytosol
Where does glycogen synthesis and degradation take place?
Glycogen granules
What are lysosomes responsible for?
Segregation of hydrolytic enzymes such as ribonuclease and acid phosphatase
What is ER responsible for?
Lipid synthesis, direction of biosynthetic products to their ultimate location
What are ribosomes responsible for?
Protein synthesis
What is responsible for a.a. oxidation, catalse & perodiase reactions, sterol degradation?
Microbodies
What are the duties of the golgi complex?
Maturation of glycoproteins & other components of membranes and secretory vessels
Where does citric acid cycle, ETC, odiative phosphorylation, fatty acid oxidation, amino acid catabolism, pyruvate oxidation take place?
Mitochondria
Where does the inner leaflet of cell membrane face?
cytoplasm
Where does outer leaflet of cell membrane face?
extracellularly
Phospholipids, glycolipids, and cholesterol are all components of ____ _____
Cell membrane
Cholesterol is a type of _____
Steroid
Triglyceride store ____
fat
Phosphatidylcholine is an example of a ______
phospholipid
What does amphipathic mean?
has hydrophobic & hydrophillic parts
Describe structure of phospholipid
amphipathic, polar head and 2 non-polar tails (tails are made of carbon)
All lipids are ____
amphipathic
Is cholesterol found on the inner or outer leaflet?
both
Are glycolipids found on the inner or outer leaflet?
outer
glycolipid carbohydrate residues form ____
glycocalyx
A phospholipid has a polar head and two non-polar tails, what is important about the tails?
One is kinked (unsaturated, double bonds) and one is no kinked (saturated)
How does more kinks in a phosphlipid tail affect the cell membrane?
It makes it more fluid
How does less kinks in a phospholipid tail affect the cell membrane?
It makes it less fluid
Phosphatidic acid is an example of what?
Phospholipid
Phocholinesphatidyl is an example of what?
Phospholipid
Phosphatidyl-ethanolamine is an example of what?
Phospholipid
Phosphatidyl-serine is an example of what?
Phospholipid
Where is phosphatidyl-serine found and why?
It is usually found on inner membrane. When a cell is undergoing apoptosis, an enzyme will flip it to outer membrane, signaling to macrophages to engulf it
Phosphatidyl-inositol is an example of what?
Phospholipid
Sphingomyelin is an example of what?
Phospholipid
Where is sugar found on cell membrane?
On extracellular surface
A fatty acid will form what when dropped in water?
Micelle
A phospholipid will form what when dropped in water?
Bilayer
What is the name of a circular bilayer used for drug delivery?
Liposome
What kind of bonding holds the lipids in the membrane together?
van der Waals bonding b/w tails
In electron microscopy, the membrane appears ______ because the polar heads stain and the lipid section remains clear
trilaminar
Membrane ______ is essential for exocytosis, endocytosis, membrane trafficking & biogenesis
fluiditiy
Which part of cholesterol is hydrophilic?
Hydroxy Head Group
As there is in crease in temperature, what happens to membrane fluidity?
Fluidity increases
Unsaturated fatty acid tails do what to membrane fluidity?
Increase fluidity
Cholesterol does what to membrane fluidity?
Make membrane more stable or rigid
What happens to red blood cells if there is too much cholesterol?
Because cholesterol makes membrane more rigid, cells have a distorted shape. RBC have thorn/finger like projections. Flexibility very important to function of RBC!
What is ascites?
A protruding abdomen
What is Asterixis?
Hold out hand and it flaps
What is a reticulocyte?
an immature RBC
Why does haemolytic anemia occur?
RBC are being destroyed too quickly
What does caput medusae and oesophageal varices mean?
new blood vessels are being formed
What pathology is associated with chronic liver disease?
Acanthocytosis
What is acanthocytosis?
spur cells due to increased cholesterol in RBC membrane
In acanthocytosis, RBC are deformed due to high cholesterol levels. What happens in the spleen because of this?
They get trapped and destroyed too early in the spleen
A pt is jaundiced, has portal hypertension with ascites, asterixis, an increased reticulocyte count and distorted cholesterol balance - what do you suspect pt has?
Acanthocytosis
What is a glycosylphosphatidylinositol anchor (GPI)?
A glycolipid that attaches proteins to plasma membrane
Lipid rafts are rich in what two compounds?
cholesterol and glycosphingolipids
Where do GPI tend to be found?
Lipid rafts
____ _____ contain integral and peripheral membrane proteins, stick out of membrane a little, and are less fluid.
Lipid rafts
What can be covalently attached to a GPI?
protein
Why do lipid rafts contain integral and peripheral membrane proteins clustered together?
The clustering enables proteins to function together for endocytic vesicles
_____ use ATP to flip a phospholipid across a membrane
Flippase
What maintains the asymmetry of a membrane
flippases
Flippases are ________ specific
phospholipid
Scramblases are ______ scramblers
non-specific
What two enzymes do flip-flop in cell membrane?
Flippase and Scramblase
Is scramblase or flippase activated during apoptosis?
Scramblase
What is a phosphlipid with a covalently attached sugar chain?
glycolipid
What is on the surface of all plasma membranes?
Glycolipids
Glycolipid is only on the ____ ____ of plasma membrane
outer leaflet
A Ganglioside is an example of a
Glycolipid
What is ganglioside a receptor for and where is it found?
Receptor for cholera toxin, found on intestinal epithelial cells
The protein:lipid ratio is dependent on what?
What kind of cell it is
Integral proteins bound to ____ ______ help maintain the structural integrity of the plasma membrane
actin cytoskeleton
List the functions of membrane proteins
Transport nutrients, metabolites, and ions across bilayer
Anchor membrane to macromolecules on either side
Receptor: signal transduction
Enzymes
Cell identity markers (MHC)
What is 30% of total protein and is amphipathic, often with an alpha helical secondary protein structure?
Integral transmembrane protein
What is the function of integral transmembrane proteins?
Receptors - signaling and adhesion, channels, transporters/pumps
What are located entirely outside but associated with inner/outer leaflet by noncovalent interactions?
Peripheral proteins
Peripheral proteins are part of the ______
cytoskeleton
What is located on either side of the bilayer and has a lipid group that inserts into the bilayer?
Lipid-anchored (peripheral) protein
What is the function of lipid-anchored protein?
Signaling and cell adhesion
What are the two different types of lipid anchors?
GPI (Glycosylphosphatidylinositol) anchor & Acylation or prenylation anchor
Acylation links proteins to the _____ ______
inner leaflet
Prenylation links proteins to the ____ _____
inner leaflet
GPI links proteins to the ____ _____
outer leaflet
What are the two kinds of transmembrane proteins in RBC?
Band 3 & Glycophorin
Glycophorin is a ________ transmembrane protein
single pass
Band 3 is a ________ transmembrane protein
multipass
Spectrin is found in what kind of cell?
RBC
What kind of chains make up spectrin?
alpha and beta
What proteins bind to spectrin?
Band 3 & Glycophorin
What two things bind together and help keep integrity of spectrin/junctional complex
F-actin & protein 4.1
What is the purpose of spectrin in RBC?
Reinforces bilayer, allows RBC to withstand stress
What is the purpose of ankyrin?
attaches spectrin cytoskeleton to membrane
What does ankyrin bind to?
band 3
What does protein 4.1 bind to?
glycophorin, spectrin, band 3
Draw example blood cell membrane, including Glycophorin, Band 3 protein, Ankyrin, spectrin, Band 4.1, & actin
Check answer on organelle power point, slide 40
What is the major cause of hereditary Spherocytosis?
inherited mutation in spectrin
A very small, round blood cell that loses biconcave shape is called a _____
spherocyte
Why are spherocytes small and round?
spectrin has a defect so the membrane is not strong - when membrane goes through small spaces like capillaries the membrane ruptures and little parts of membrane come off.
If a person has spherocytes what kind of anemia might the have?
haemolytic
If a person has the following symptoms: haemolytic anemia, jaundice, gall stones, and round, small RBC, what disease might they have?
hereditary spherocytosis
What is splenomegaly?
Increased spleen size
Why do pts with Hereditary spherocytosis have splenomegaly?
the RBC get trapped in spleen causing the spleen size to increase
Apical, lateral, and basal are all examples of _______ proteins but they all have different ______
transmembrane, functions
What is the function of the apical plasma membrane (and proteins)?
regulation of nutrient and water intake, regulated secretion, protection
What is the function of the lateral plasma membrane (and proteins)?
cell contact & adhesion, cell communication
What is the function of the basal plasma membrane (and proteins)?
cell-substratum contact, generating ion gradients
What is the name of the sugar coat on all cells?
glycocalyx
The majority of proteoglycan is _____
sugar
The majority of glycoprotein is _____
protein
Name three general classes of carbohydrates in the cell membrane
glycoproteins, glycolipids, proteoglycans
Why do all cells have a glycocalyx coat (What is the function of glycocalyx)?
protection from acids, enzymes, etc
recognition (leukocyte) & cell adhesion
repulsion: negative charge from sialic acid sugars
embryonic development: guides embryonic cells to destination
Cancer cells have a different _____ coat than non cancer cells
glycocalyx (sugar!)
Some anti-cancer therapies target enzymes that assemble what to start an immune defense to attack the cancer cells?
tumour glycocalyx - the antibodies recognize and attack
What are the primary marker for cell recognition?
carbohydrates
What are selectins?
a group of proteins that bind to the sugar chain of a glycoprotein instead of to the protein itself
What is the attachment for viruses, bacteria, toxins, and other cells?
carbohydrates
____ recognize addressins on lymphoid organ endothelial cells
L-selectins