Download Problem Set 4:

Problem Set 4:
Complete the diagrams below by labeling the components of both the plant and animal cells.
State the function or purpose of each of the identified components:
This table lists the general functions performed by an animal cell. List the cellular structure(s) associated
with each of these functions.
Function
Cell division
Information storage and transferal
Energy conversions
Manufacture membranes and products
Lipid synthesis, drug detoxification
Digestion, recycling
Conversion of H2O2 to water
Structural integrity
Movement
Exchange with environment
Cell-cell connection
Associated Organelle(s) and Structures
a. nucleus; chromosomes, centrioles,
microtubules, microfilaments
b. nucleus, chromosome, DNA, mRNA,
ribosomes, enzymes and other chaperone
proteins
c. mitochondria
d. ribosomes, RER, SER, Golig apparatus,
vesicles
e. SER (peroxisomes also)
f. lysosomes, food vacuoles
g. peroxisomes
h. cytockeleton: microtublules, microfilaments,
intermediate filaments, extracellular matrix
i. cilia and flagella, microfilaments in muscles
and pseudopodia
j. plasma membrane, vesicles
k. desmosomes, tight and gap junctions, ECM
Interactive Question 7.2
a. If a eukaryotic cell has a diameter that is 10X that of a bacterial cell, proportionally how much more
surface area would the eukaryotic cell have? 100X
b. Proportionally how much more volume would it have? 1000X
Interactive Questions Ch 8
8.1 Label the components in this diagram of the fluid
mosaic model of membrane structure. Indicate the
regions that are hydrophobic and those that are
hydrophilic.
Cholesterol; extracellular hydrophilic region;
hydrophobic region; intracellular hydrophilic
region’ proteins both extrinsic and intrinsic
8.2
a. Cite some experimental evidence that shows that membrane proteins drift. Hybrid membranes mix readily
b. How might the plasma membrane of a plant cell change in response to the cold temperatures of winter? ↑Unsat
phospholipids
8.3 List the six major kinds of fxns that membrane proteins may perform transport; enzymatic activity, signal
transduction, intercellular attachment, cell-cell recognition, attachment to cytoskeleton and ECM
8.4 What types of molecules have difficulty crossing the plasma membrane? Why? Ions and large polar molecules
s.a. glucose b/c hydrophobic center
8.6 What osmotic problems do fresh water protists face? Hypertonic protests will gain water from their
hypotonic environment. What adaptations may help them osmoregulate? Some have membranes that are less
permeable to water and contractile vacuoles that expel excess water.
8.7 The ideal osmotic environment for animal cells is isotonic. The ideal environment for plant cells is hypotonic.
8.8 Why is facilitated diffusion considered passive transport? b/c with [gradient] no E required
8.9 The Na+ -- K+ pump, the major electrogenic pump in animal cells, exchanges sodium ions for potassium ions,
both of which are cations. How does this exchange generate a membrane potential? 3 Na+out for 2 K+ in,
resulting in a net + charge outside the cell membrane
8.10 A. How is cholesterol, which is used for the synthesis of other steroids and membranes, transported into
human cells? Receptor-mediated endocytosis
B. Explain why cholesterol accumulates in the blood of individuals with the disease familial
hypercholesteremia? LDL receptor proteins are defective and LDL proteins can’t bind and be transported
into the cell.