Download LB145-lecture4

Announcements
•
•
Lecture course: (1) Contracts (2) MasteringBio!
Lab course:
•
(1) Reminder DRAFT1 due precisely at start of
lab both in print & on turnitin.com (Wed/Thurs)
•
(2) Next week you start your PCR experiment
in lab, you must be prepared to be admitted
All in group need to show your Course Packet
with filled-in answers p.40 for (i) recipe of
cocktail, (ii) two primers, (iii) calc anneal temp.
Outside/Prior to lecture
• Stand up if completed reading (12 pages)
Took Notes, Answered Qs, Studied Notes
Inside/During lecture
• Learning how to use information and
!
knowledge in new situations
Umm, so how much did that crazy
Luckie-dude say I am to study?!
2hrs/day
[1hr for lab]
[1hr for lecture]
If you were a prokaryotic cell, you would be lacking _____.
a. a plasma membrane composed of phospholipids and proteins
b. chromosomes that contain genetic information
c. ribosomes to synthesize proteins
d. mitochondria to generate ATP
Which of the following is NOT considered a benefit of
compartmentalization in eukaryotes?
a. Chemical reactions are more efficient because substrates are more
easily maintained at high concentrations within organelles.
b. Chemical reactions that are incompatible can be segregated in different
organelles.
c. DNA is transcribed and translated at significantly higher rates because
all of the machinery is inside a single, membrane-bound nucleus.
d. When the product of one reaction is the substrate for a second reaction,
the enzymes that work together can be clustered together on internal
membranes and result in greater speed and efficiency.
Why is the smooth endoplasmic reticulum unable to
synthesize proteins?
a.
b.
c.
d.
It has no ribosomes.
There is no supply of free amino acids that it can easily access.
It stores calcium, which is known to inhibit protein synthesis.
It has no DNA to direct the synthesis of proteins.
Hypothesis?
What is a molecular HYPOTHESIS? (p94)
What’s the story, the hypothesis and was it supported?
Chromosome
Ribosome
Cytoskeleton
Plasma
membrane
Flagellum
Glycolipids
Cell wall
Ribosomes
So what does a bacteria cell have & we don’t?
Plasmids
Cytoplasm
Flagellum
Chromosome
Plasma
membrane
Cell wall
So what does a bacteria cell have & we don’t?
A. The plasma membrane surrounding it
B. Chromosomes with DNA to make RNA
C. Ribosomes making proteins
D. The cell wall surrounding it
E. None of the above
Nucleus
Plasma membrane
Rough endoplasmic
reticulum
What does animal cell have that plants don’t?
Golgi apparatus
Chloroplast
Bacteria
Cell wall
What does animal cell have that plants don’t?
A. A single plasma membrane surrounding it
B. Mitochondria
C. A true Nucleus
D. The cell wall surrounding it
E. None of the above
Antibiotics that inhibit prokaryotic ribosomes
Ribosome
Antibiotics that inhibit prokaryotic ribosomes
A. Will stop bacterial protein synthesis
B. Will stop mitochondria protein synthesis
C. Will stop nucleus from making proteins
D. None of the above
E. More than one of the above
Collagen
Proteoglycan
complex
EXTRACELLULAR FLUID
Fibronectin
Integrins
Plasma
membrane
Microfilaments
CYTOPLASM
Microvillus
Plasma membrane
Microfilaments (actin
filaments)
Intermediate filaments
0.25 µm
Plasma
membrane
Cytoskeletal
elements
Euchromatin
Heterochromatin
Nucleolus
Nuclear envelope
Nucleus
1 µm
Nucleolus
Chromatin
Nuclear envelope:
Inner membrane
Outer membrane
Nuclear pore
Pore
complex
Surface of
nuclear envelope
Rough ER
Ribosome
1 µm
0.25 µm
Close-up of nuclear
envelope
Pore complexes (TEM)
Nuclear lamina (TEM)
0.2 µm
Matrix
Cristae
Mitochondria
0.2 µm
Intermembrane space
Outer
membrane
Free ribosomes
in the
mitochondrial
matrix
Inner
membrane
Cristae
Matrix
0.1 µm
WTF?
So where did my organelles come from?
32
Plasma membrane
Cytoplasm
Ancestral
prokaryote
DNA
Invagination
Endoplasmic reticulum
Nuclear envelope
Nucleus
Aerobic
heterotrophic
prokaryote
Endocytosis
Mitochondrion
(with extra mem)
How to test the endosymbiosis hypothesis…
What evidence could you look for?
(that might support or refute the hypothesis)
Design an experiment
to test the endosymbiosis hypothesis…
• Maybe using PCR
• Maybe using Microscopy
• Perhaps using streptomycin, erythromycin,
or tetracycline
• What’s the experiment, what is your
prediction based on the hypothesis?
Evidence for Endosymbiosis
Mitochondria/Chloroplasts
Bacteria
Morphology/Behavior: They swim around in your cells,
divide, look like cyanobacteria etc
Anatomy: Have 2 membranes, inner like bacteria & outer
like plasma membrane.
Molecular: Their own genes & ribosomes, that functionsequences of genes, ribosomes, same as bacteria,
antibiotic, circular no histones
Pathogens: Undigested prey or parasites via endo
37
Molecular “zip codes” direct molecules to specific
destinations in the cell. How are these signals read?
a. They bind to receptor proteins.
b. They enter transport vesicles.
c. They bind to motor proteins.
d. They are glycosylated by enzymes in the Golgi apparatus.
What does a motor protein do in a cell?
a.
b.
c.
d.
causes microtubules to “treadmill”
converts ATP into mechanical energy in the form of movement
triggers receptor-mediated endocytosis
aids in the transport of newly synthesized proteins from the
endomembrane system