Nkechiamaka Nwosu
Dr. O please could tell me what are the different ways of the regulating cell signaling? 8:13
Marcos Oliveira
regulation of cell signalling can occur at the level of the receptor: 1. proteins that block receptor activity
(arrestin)
8:14
2. opposing signals that activate Gprotein (inhibitors) and/or Gprotein(stimulators)
8:15
3. Gi and Gs regulate adenelate cyclase which generate the second messenger cAMP
8:16
4. Phosphodiesterase degrades second messenger cAMP
8:16
Cristina Renteria
good evening dr.o. how will the test be balanced, considering the material of 10 chapters for the exam?
will there be alil of each chapter in the exam? 8:15
Marcos Oliveira
material for the exam: 1/3 of questions on signaling 2/3 on metabolism 8:17
Amanda Buhler
none on DNA stuff?
8:17
Marcos Oliveira
that distribution is for the first week
8:18
Marcos Oliveira
30 questions/per week 8:18
second week: 30 questions equally distributed between DNA replication/Transcription/translation
8:19
Minh Tran
what about material related to the cancer article
8:24
i think a lot of us could use help on understanding it more
8:24
like what are the key glycolytic targets we have to know from the article 8:25
Marcos Oliveira
You should use the material I posted with questions and links to the text for guidance. Based on what I
read from the group activity in class It seems that the class did have an understanding of the article
8:26
Rebeca Jimenez
will have access to the article during the essay? 8:28
Marcos Oliveira
I can consider this for the essay portion 8:28
Rebeca Jimenez
but that means our essays have to be that much better, right?? 8:29
Marcos Oliveira
If a group elevates the answer based on the paper yes
8:29
Nkechiamaka Nwosu
on the lecture of glycolysis, could you explain the phrase asymmetrical enzymes for the different
enzymes that are needed for the irreversible reactions 1,3, and 10?
8:31
Marcos Oliveira
asymmetrical regulation which means that in order to achive flux in a specific direction at steps 1,3,10
the enzyme in one direction is shut off and in the opposing direction it is turned on
8:33
Jennifer Ma
Dr. O, are you holding an Exam 4 review session tomorrow at 5pm?
8:35
Marcos Oliveira
yes exam review session tomorrow will be at 5PM Ms griffith will continue from 6PM to 7PM
8:36
Gerald Reyna
Dr. O, how in depth should we know about the free energy changes in glycolysis and gluconeogenesis?
On your summary paper the point about the "energetic perspective" sounds very dauting to me since I
freak out when I see numbers on the exams.
8:37
Marcos Oliveira
Then those types of questions will not be in our exam. They have been in past exams because I did
spend time with this topic in previous classes
8:40
Nkechiamaka Nwosu
do we need to know the very specific details regarding lipid metabolism in Chapter 17? 8:44
Marcos Oliveira
as much as presented in the summary I provided to the class and class discussions
8:44
Amanda Buhler
for the TCA, the pentose-phosphate pathway, should we know every intermediate step? Or just the
overall view? 8:46
Marcos Oliveira
the two pathways that we spent time discussing at that level were Glycolysis, gluconeogenesis and TCA
8:47
Amanda Buhler
ok thanks
8:49
Cristina Renteria
will the final exam be based on our previous exams and a bit of the fourth exam?
8:52
Marcos Oliveira
the comprehensive will be based on all four exams
8:53
Cristina Renteria
how many questions will the final exam be over and how much time will we have? I noticed that we
have pharmacy communications lecture from 11 to 12am on tuesday sept 20. the day of our final
8:56
Marcos Oliveira
we have two hours
8:57
Cristina Renteria
thank you. can you please explain the relationship between transaminase and pyruvate? 8:58
Marcos Oliveira
Transaminase reaction allows the converstion of puruvate to alanine see summary I posted
8:59
Cristina Renteria
im sorry but why would we need alanine as a product in the body... i hope this is not a dumb question....
9:01
Marcos Oliveira
Not at all. The transaminase reaction ties carbon metabolism to amino acid metabolism 9:02
transaminase involve the transfer of an amino group
9:02
Cristina Renteria
also dr. o, i understand that ketone bodies are made from acetyl-coA. but, are they made before
gluconeogenesis occurs??? the process of these concepts and the order in which they occur confuses
me.
9:08
Marcos Oliveira
gluconeogenesis is a process that occurs when there is a shortage of gluose and it is an activity of the
liver which controls blood levels of glucose
9:10
ketone bodies are produced when there is an oversupply of acetyl-coA units. Again produced by the
liver to supply energy in the case of short supply of glucose
9:11
when there is abundance of glucose there is no need to activate ketone production
9:11
Jennifer Ma
can these two processes (gluconeogenesis and ketone bodies formation) occur simultaneously within
our bodies in an effort to replenish blood glucose levels?
9:12
Cristina Renteria
but the keytone bodies are only used for fuel when their is an absence of glucose? correct? and after the
keytone bodies are used, then gluconeogenesis occurs??
9:12
Jennifer Ma
or is one process exhausted first before ketone bodies formation begins?
9:12
Marcos Oliveira
in the absence of glucose gluconeogeneis is activated and is required due to the fact that some tissues
only function with glucose (RBC). On the other hand other tissues can utilize ketone bodies instead
9:13
Marcos Oliveira
in extreme low carbon levels gluconeogeneis is active because some tissue can only function on glucose.
Other tissues can function on ketoone bodies and will switch metabolism to the use of keotne bodies.
Thus both processes need to occur
9:15