Module 3-4 Flashcards
It is a simple matter (i.e., thermodynamically favorable) for a vesicle to form from the endoplasmic reticulum.
false
Cholesterol is _____ to have in biological membranes
good
Facilitated diffusion uses a channel protein to let components move _____ their concentration gradient.
down
A single pass trans-membrane protein that is an alpha helix ______ make a channel.
cannot
The ER is _______ with the nuclear envelope.
contiguous
Active transport uses ATP to move components in parallel with their concentration gradient, that is: from a _____ concentration to a _____ concentration.
Low - High
We are made up of ______ percent water.
50-70
The ER ____ contiguous with the Golgi apparatus.
is not
Draw a phospholipid and make sure the numbers of carbons are clearly identified.
Explain the evolutionary origin of mitochondria.
Mitochondria and Chloroplast presumably evolved by way of Endosymbiosis. They are isolated from the endomembrane system, which is why they are called orphaned organelles and there are other pathways for them to get proteins and membranes.
Explain how the vesicles are carried from the Golgi apparatus to the plasma membrane.
The plasma membrane gets new lipids from:
Vesicles
What are the orphaned organelles orphaned from?
Mitochondria and Chloroplast presumably evolved by way of Endosymbosis. They are isolated from the endomembrane system, which is why they are called orphaned organelles and there are other pathways for them to get proteins and membranes.
What are the two functions of a membrane?
1) partition water (and those those things soluble in water)
2) compartmentalize enzymes to increase the efficiency of chemical reactions.
Amino acids can be largely subdivided into two groups. What are the two groups?
Essential
Non-essential
Conditionally essential
If something is soluble in water and a shell of hydration forms around it, it is termed ___________________ .
hydrophilic
When a vesicle fuses with the plasma membrane the contents of the lumen of the vesicle are:
Ligands that are used in cell communication.
Explain the evolutionary origin of the endoplasmic reticulum, Golgi apparatus and vesicles.
The endomembrane system that resulted as the primitive proto-prokaryotic cell evolved into the primitive, proto-eukaryotic cell gave rise to many membranes in addition to the plasma membrane. The endomembrane system gave rise to a new type of protein synthesis AND a site where new lipids are made.
What is the difference between a triglyceride and a phospholipid?
Triglycerides have glycerol and three fatty acids, which makes them fats. Phospholipids are not fats, since they have glycerol, two fatty acids and phosphorus. Phospholipids are more essential to the formation of lipid bilayers, which maintain cell membrane structure, than triglycerides are. Fat cells store triglycerides, while phospholipids help break down fats in the body.
For a protein to enter the endoplasmic reticulum as part of the endoplasmic reticulum’s lumen or part of the endoplasmic reticulum’s membrane:
A ribosome binds to the mRNA and a short stretch of protein is synthesized that contains a signal sequence.
What is the difference between a single-pass transmembrane protein and a 7-pass transmembrane protein?
The actin filament system is _____ in the nucleus.
not present
Chromosomes are made out of ________.
DNA and proteins
Molecular motors use ___ as the energy source to power the molecular motors.
ATP
________ does not exist in Nature but scientists can make _______ in a test tube.
naked DNA
Where is the histone H1 found?
with each nucleosomal core unit there is one H1 that is acting, sort of, like a staple.
Heterochromatin _____ in interphase nuclei.
does exist
The diameter of an intermediate filament is ______.
10 nm
Cilia and microvilli contain a ______ number of parallel actin filaments.
different
Consider the geography of cells. Actin filaments are present in the cell’s ___ and the microtubules are present in the cell’s _____.
cortex
interior
Molecular motors run on which two cytoskeletal filament systems?
microtubule system
actin filament system
To get into the nucleus a component has to have the correct ______ and pass through a ______.
signal sequence
nuclear pore
Which cytoskeletal filament system lines the inside of the nucleus to protect it?
Intermediate Filament System
The actin filament system _______ of the cell.
stays inside
What does the nucleosomal core have in it?
–Two H2A
–Two H2B
–Two H3
–Two H4
