Angela1

Question states: Oxygen and carbon dioxide crossing between blood and air in the lungs must pass through cells of which of the following types:

CHOICE A: type I pneumocyte only

CHOICE B: type I pneumocyte and endothelial cells

So, it's a matter of if endothelial cells are included or not?

I am very lost..

Greetings to all,

Question states: The cytochrome P450 system of liver in normal individuals has a capacity (Vm) to oxidize approximately 10 nmol of drug X per minute per gram of liver. When the concentration of drug X in the liver is 2um oxidation products are formed at the rate of 4 nmol/min/g of liver. What is the Km of cytochrome P450 for this drug?

Two answer choices were 5 nM or 3 uM. The correct answer is 3 uM.

I am totally lost on how to do this problem. Can someone please help?

Diagram

 

Assuming this diagram is correct, AML mutation occurs within the Myleoblast before differentiation occurs and then excess clones of this cell being formed, however all your other options are differentiated from this cell, implying they would be reduced rather than increased.

 

Colony-forming unit erythrocytes are definitely reduced as this is a key symptom of the disease, however I can't workout which one would be increased.

 

What would be increased is the number of progenitor cells and myeloblasts, but that isn't one of the answers, are you sure the question is correct.

 

AML

Myeloblasts

Thank you for replying! Hmm, you made good points...This was the question. I am wondering if to go with the only selection that had myeoblasts.

Greetings,

I am having a lot of trouble finding the correct answer to this question after reading about them in my book still.

The question asks:

A patient with acute myeloblastic leukemia might have a very high bone marrow concentration of:

neutrophilic myelocytes

basophilic myelocytes

eosinophilic myeloblasts

colony-forming unit erythrocytes--THIS WAS MARKED WRONG

neutrophilic stab cells

I am very lost at which one would increase? Help would be appreciated.

Muscles are a tissue.

Ohh, I did not factor that in! Thank you so much for alerting me.

The muscles are also kind of important.

True, but my teacher wants us to focus only on the tissues.

Hello everyone,

I am working on a project where I need to write about what tissues (not bones) that form the knee and help it function. After my research, I have come up with meniscus tissue, cruciate ligaments, articular cartilage, and tendon.

I have not written enough content yet and was wondering if there are any other structures or something I missed?

Thanks.

The original question asked:Which of the following is (are) often absent in thick skin but typically present in thin skin?

Arrector pili muscles

Meissner’s corpuscles

Stratum basale

Stratum corneum--I know it is not this one for sure

I think it is the Meissner's corpuscles since they have to do with pain/touch, but am unsure. Can someone help me confirm?

Thanks to both of you who responded. Very appreciated!

Hello everyone,

Can I post histology based questions on this forum? I would think it could fall under here, but wanted to confirm first.

Thanks!

The process of gluconeogenesis start within the mitochondria, oxloacetate is reduced to malate using NADH which is turned to NAD+

 

In this case

 

Oxloacetate --> Malate = Reduction

NADH --> NAD+ = Oxidation

 

These could be said to be coupled reactions because they happen at the same time for the same purpose and as you can see though the main substrate is being reduced (Oxloacetate) a secondary substrate (NADH) is also being oxidised creating enzymatically coupled redox reaction.

 

The Malate is then transported out of the mitochondrion and the reverse happens

 

Malate --> Oxloacetate = Oxidation

NAD+ --> NADH = Reduction

 

This happens within the cytoplasm rather than in the mitochondrial matrix, this occurs due to there not being a transport protein across the mitochondrial membrane for malate.

 

This process also moves a reducing agent NADH out of the mitochondria and into the cell cytoplasm where it can be used to reduce other (non-mitochondrial based) reactions as well as supplying NAD+ to the mitochondria.

I see what you mean now. Wow, thank you so much for taking the time out to write this full explanation!! I appreciate it so much.

You are right to say that NADH --> NAD+ is oxidation and visa versa reduction, it could be a typing error (they happen) or it could be that the NAD part is a coupled reaction to the main gluconeogenesis reaction which is what they are actually referring to.

 

Oxidation is the loss of electrons or an increase in oxidation state

Reduction is the gain of electrons or a decrease in oxidation state

 

Many biological reactions are redox reaction where one molecule is oxidise while another is reduced.

Thank you soo much for helping to clear this up. I am thinking it may be a typo..

If you do not mind, would you care to expand a little more on what you meant by the possible coupling mechanism being why it is called 'reduced?'

Hello everyone~ I have a burning question. I was studying and came across this reduction/oxidation example under gluconeogenesis topic. The book stated that: NADH----> NAD+ is reduction and NAD+ ------> NADH is oxidation. I am very confused because I thought opposite. I thought that is the H is lost in NADH, that is oxidation, as oxidation is loss of electrons (or oxygen). Can someone please clear this concept up of oxidation/reduction. Thank you.