Organelles and Structures Flashcards
Two layers of phospholipids
Hydrophobic tails, hydrophilic heads
Sphingolipid makeup:
Fatty acid tails that are slightly longer than phospholipids, with a phosopholipid or glycolipid head
Three components of membrane:
Phospholipids, sphingolipids, and cholesterol
Net effect of cholesterol on membrane
Increases fluidity and decreased permeability to water
Membrane proteins that are usually cytosolic and easily dissociated from membrane
Peripheral membrane protein
Sphingolipid anchored peripheral proteins form ______
Lipid rafts
Membrane proteins that are ambipathic and lodged in the membrane
Integral membrane proteins
Transmembrane integral membrane proteins include:
Channels and carrier proteins
One sided integral membrane proteins include:
Enzymes and receptors
Two types of membrane carbohydrates
Glycoproteins and glycolipids
Location and binding mechanism of membrane carbohydrates
Covalently bonded to lipids or proteins on the extracellular surface
Two functions of membrane carbohydrates
Glycocalyx and cell recognition
Function of glycocalyx
Protection and cell adhesion
What is the glycocalyx
Glycoprotein that covers some cell membranes
Functions of cytosol (4)
- location of specific chemical reactions
- storage of fat, carbohydrates
- storage of secretory vesicles
- ionic composition (nerve and muscle cells)
Protein factories of the cell
Ribosomes
Proteins formed by _______ ribosomes are released into the cell
free
Proteins formed by ______ are transported to the golgi and then secreted or distributed to other organelles
rough ER ribosomes
Function of rough ER
synthesis of proteins and lipids to be packaged into vesicles
Function of smooth ER
Lipids synthesis and formation of transport vesicles
Main function of sarcoplasmic reticulum
Storage of calcium in muscle cells
Functions of golgi (2)
- Modification of the macromolecules made by the ER
2. Packaging of macromolecules into vesicles for transport to cell surface or the cytosol
Function of mitocondria
Production of ATP via aerobic metabolism/cellular respiration
Inner membrane of mitochondria form the
cristae
The enzymes of Krebs cycle are found in the ____
Mitochondrial matrix
The electron transport chain is found on _______
Cristae of inner membrane of mitochondria
Kearns-Sayre syndrom results from _________
Deletions in mitochrondrial DNA
_______ are barrel-shaped organelles that were recently discovered and are implicated in multi-drug resistance to chemotherapy
Vaults
Six functions of the cytoskeleton
- mechanical support and structure
- intracellular transport of materials
- suspension of organelles
- formation of adhesions with other cells
- contraction
- movement
Three types of motor proteins
Myosins, kinesins, dyenins
Function of myosins
Binds to actin for muscle contraction
Function of kinesins
Movement of vesicles
Function of dyenins
Movement of vesicles; whiplike motion of cilia and flagella
Common type of microfilament
Actin
Four functions of microfilaments
- muscle contraction
- ameobid-like movements
- separation of cytoplasm during cell division
- structural support for cell projections like microvilli
Myosin, neurofilaments, and keratin are common types of ________
Intermediate filaments
ALS results in….
The progressive degeneration and death of motor neurons
Recent theory of ALS
Abnormal accumulation and disorganization of neurofilaments
Three functions of microtubules
- mitotic spindle fibres
- transport of secretory vesicles
- major component of cilia and flagella
Microtubules have a _______ structure
Dynamic
_______ provide a highway for vesicular transport along the axon
Microtubules
Function of reverse vesicular traffic
Moving debris from the axon back to cell body for destruction by lysosomes
Function of lysosomes
Breaking down molecules
Tay Sachs disease is caused by a genetic mutation of ______ gene
HEXA
Tay Sachs results _____
Inability to make an enzyme that breaks down GM2 ganglioside
Accumulation of gangliosides in neurons leads to
premature neuron death
Function of peroxisomes
Location of oxidative reactions; detoxifying molecules