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Cell Structure


As multicellular organisms decelop from embryo to adults, gap junctions are made and broken in specific patterns, involving specific tissues. This suggests that these junctions play an important role in signalling between cells during embryonic development. A) With the understanding of Gap junctions, speculate on what sorts

Cell to cell contact

Electrical coupling requires Ion flow. FOr cardiac muscle cells to contract in unision, there must be electrical coupling between cells. What type of cell to cell contact is most likley responsible for this coupling? What cell to cell junctions connect epithelial cells to a basment membrane

Signal pathway comparison

Consider the signalling pathway that proceeds through three protein kinases that are sequentially activated by phosphorylation. IN one case the kinases are held in a signalling complex by a scaffolding protein; in the other, the kinases are freely diffusing (see figure attached). Discuss the properties of these two types of orga

Second messengers

Is it true that all small intracellular mediators (second messengers) are water-soluble and pass freely through the cytosol? Why? I know this is true, but why is it true?

Isolate peroxisomes

Hi, I have a test next wednesday and a concept is not clear to me. How would I isolate peroxisomes from cells. ( I dont need a complicated technical answer, but more of a general idea). Thanks

Transport vesicles, secretory vesicles, and endocytotic vesicles

Whats the difference between transport vesicles, secretory vesicles, and endocytotic vesicles? I know that Transport vesicles move molecules between locations inside the cell. For example they move proteins from the ER to the Golgi, from there to the outer membrane, where they are secreted

Phospholipid bilayer

What are the three chief components of eukaryotic cell membranes? Where does each originate? What organelle synthesizes new membrane? What accounts for the stability of phospholipid bilayers in acqueos systems? Would the three components be the integral membrane protein, cholesterol, and lipid? Is the ER the organelle th


What types of chemical can generally pass through phospholipid portions of the cell membrane and why? What types are generally prevented from passing through and why? I would guess hydrophillic chemicals can pass through.

Coat Proteins

The image shows the inner face of a cell membrane with numerous budding structures, each one surrounded by coat proteins. What process is going on, and what is the role of the coat proteins?

the location of ribosomes

You prepare radioactivley labelled ribosomal subunits and you microinject them into cells that you are culturing in the laboratory. At different times after you inject the subunits, you take a small amount of cells and analyze them by electron microscopy. You find very soon after injection, the labelled subunits are assembled in

COPII assembly

I am currently studying the intracellular distribution of a particular protein. The protein is normally Golgi-resident. What would happen to this distribution if i treated the cell with an inhibitor of COPII assembly? I would think that if the COPII vesicles are inhibited the ER would be unable to export cargo to the gol

What ingredients are needed for bread to rise?

Bread ingredients include milk, sugar, flour and salt. Which of these is needed for maximum fermentation by the yeast? What tests could be done in the lab? Will yeast react differently with different amounts of the other ingrediants? We did the lab and cut down the amounts of sugar, salt and milk. We had different results bu

Cellular Respiration

If the conversion of pyruvate to lactate or ethanol and CO2 doesn't yield any energy for anaerobic cells, why do they do it? Please keep answer short and precise as possible!!!!!

Cellular respiration

Why is fat a good energy storage molecule in animals? How about Glycogen? Please keep answer short and precise as possible!!!!!

Potential problem...

The oxidation of FADH2 to form FAD: FADH2 (right arrow) FAD + 2H+ + 2e- this has a potential E (prime)=0.219 under biological conditions (pH=7.00) @ 298 K. What is the potential for this process under standard conditions? Please- I need a detailed explanation- not just numbers- I am using this as a study guide for my final

Mitochondria and erythrocytes

Why are mitochondria and erythrocytes red? Please answer this question completely. I need a full understanding of why and how this occurs. Thank you


Consider the role of the coenzyme NAD in glucose oxidation. In the process of glycolysis the formation of pyruvate involves the reduction of the coenzyme NAD to NAD.2H. (a) Which other stages of glucose oxidation produce molecules of the reduced coenzyme, NAD.2H? (b) Explain what happens to NAD.2H produced during glycoly

For # 104369 Energy requiring NAD.2H

The oxidation of NAD.2H is an energy -releasing process. Name the energy-requiring process it is coupled to, and explain why this is important for the cell (two or three sentences please) Thank you

What happens to NAD.2H during animal cell production -not for #103139 thankyou

Explain what happens to NAD.2H produced during glycosis 1) in an animal cell respiring aerobically, and 2) in an animal cell respiring respiring anaerobically I have already recieved an answer to this but I need a more simplified answer as I need to answer this in in more than 200 words. Thankyou for your help

Stages of glucose oxidation

In the process of GLYCOSIS (stage 1), the formation of PYRUVATE involves the reduction of the coenzyme NAD to NAD.2H Which other stages of glucose oxidation produce molecules of the reduced coenzyme, NAD.2H I am guessing at stages 2 & 3,

Cell Structure and Function

1. Which of the following organelles is most important in providing energy to the cell? (a) mitochondrion (b) centrosome (c) Nucleus (d) Peroxisome 2. Name the membrane valves that open and close for potassium efflux and sodium influx. (a)ion channels (b)Vacuoles (c)Capillaries 3. What technique can be used to measure cell act

Vocabulary review

The attached vocabulary review is an assignment I would like to have looked over to see if I am matching the terms correctly.

Chemical Equation for an organelle

I have been assigned the cell wall, and cell membrane for a biology project. One aspect of the project is determining the chemical equations for the proceses which occur inside that organelle. i have done research on, and off of the internet and have yet to find any answers. Could someone point me in the right direction, or supp