MCB 104 Unit 3: Cell Biology Exam Questions With Correct Answers
0 view 0 purchase
Course
MCB 104
Institution
MCB 104
MCB 104 Unit 3: Cell Biology Exam
Questions With Correct Answers
What are the 3 domains? - answerBacteria, Archaea, Eukarya
What units do we measure cells in for radius and volume? - answermicrometers, femtoliters
Minimum resolvable distance in: EM, light microscopy, human eye - answer2 nm, 200...
MCB 104 Unit 3: Cell Biology Exam
Questions With Correct Answers
What are the 3 domains? - answer✔Bacteria, Archaea, Eukarya
What units do we measure cells in for radius and volume? - answer✔micrometers, femtoliters
Minimum resolvable distance in: EM, light microscopy, human eye - answer✔2 nm, 200 nm, 0.2 mm
resolution - answer✔r = distance by which two closely spaced objects can be distinguished
r and wavelength of illumination are proportional
What is empty magnification? - answer✔increasing magnification in the eyepiece only; the objective
lens gives resolution
What is the max resolution of a light microscope? - answer✔200 nm
What does a light microscope use? - answer✔phase contrast - phase shifts due to light passing different
media causes brightness changes
What is the max resolution of electron microscopy? - answer✔~2 nm
What is TEM and describe the procedure? - answer✔transmission electron microscopy;
1. fix cells
2. cut very thin sections
3. stain with heavy metals that scatter electrons to create contrast
prokaryote - answer✔no organelles/nucleus; has compartments, cytoskeleton, cell wall, nucleoid, inner
and outer plasma membrane
fluorescence microscopy - answer✔A fluorescent molecule (e.g. antibody - which binds to target amino
acids) is attached to a protein of interest. Use an excitation light of known wavelength, which causes an
emission light of longer wavelength (lower energy).
superresolution microscopy - answer✔physical properties of fluorescent samples are exploited using
various optical and computational techniques to increase resolution beyond the diffraction limit
What is GFP? - answer✔green fluorescent protein; found in the jellyfish Aequorea victoria
How crowded are cells? - answer✔very, space between molecules = size of molecules
What are advantages of compartmentalization of a cell? - answer✔1. concentrate specific molecules
2. provide distinct microenvironments
3. sequester harmful molecules
4. enable regulation
Why do cellular lipid spontaneously form bilayers? - answer✔entropy change is positive when fatty acid
tails pack against each other and exclude H2O molecules
Why is cholesterol important? - answer✔membrane rigidity, precursor for steroid hormones
What is unique about membrane composition? - answer✔extracellular and cytoplasmic sides each have
different compositions of lipids
Where can exoplasmic faces face? - answer✔outside the cell OR inside vesicles/organelles
What protein structure spans membranes? - answer✔alpha helix - hydrophobic residues on membrane
What are the 4 types of membrane protein insertions? - answer✔1. covalently attached lipid tail
2. electrostatic interaction - polar head of phospholipid (-) attracted to (+) charged protein
3. partial insertion
4. bind to a different transmembrane protein
What are the functions of the membrane? - answer✔1. prevent molecules/ions from leaking out
2. separation of charge -> membrane potential
3. platform for signaling complexes
pump transport protein - answer✔absolute specificity, 100 ions/s, against gradient -> needs energy
input
carrier transport protein - answer✔intermediate specificity, <1000 ions/s, downhill, no energy needed
steps of signal transduction pathway - answer✔1. relay
2. amplify
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller Thebright. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $10.49. You're not tied to anything after your purchase.
