91影视

When the pathogen Salmonella typhimurium infects mammalian cells, the host cell protease caspase-1 is enabled to cleave and thereby activate signaling proteins that instigate the immune response. The targets of caspase-1 also include aldolase and enolase. What effect would this have on the infected cell and why might this be advantageous to the organism?

Explain the chemical logic of dehydrating 2-phosphoglycerate before its phosphoryl group is transferred.

The half-reactions involved in the lactate dehydrogenase (LDH) reaction and their standard reduction potentials are

Pyruvate +2H鈦�+2e鈦烩啋Lactate

狈础顿鈦�+2贬鈦�+2别鈦烩啋狈础顿贬+贬鈦�

Calculate 鈭咷 at pH 7.0 for the LDH-catalyzed reduction of pyruvate under the following conditions:

1. [lactate]/[pyruvate]=1 and [NAD鈦篯/[NADH]=1
2. [lactate]/[pyruvate]=160 and [NAD鈦篯/[NADH]=160
3. [lactate]/[pyruvate]=1000 and [NAD鈦篯/[NADH]=1000
4. Discuss the effect of the concentration ratios in Parts a-c on the direction of the reaction.

Explain how chemical coupling of endergonic and exergonic reactions is used to generate ATP during glycolysis.

Why is it possible for the 鈭咷 values in Table 15-1 to differ from the 鈭咷掳藞 values?

Which products of glycolysis are reduced molecules that the cell can oxidize to recover free energy?

If a reaction has a 鈭咷掳藞 value of at least -30.5kJ mol^-鹿, sufficient to drive the synthesis of ATP (鈭咷掳藞=30.5kJ mol^-鹿), can it still drive the synthesis of ATP in vivo when its 鈭咷 is only -10kJ mol^-鹿? Explain.

Describe the three possible fates of pyruvate.

Compare homolactic and alcoholic fermentation in terms of the products and the cofactors required.

What is the advantage of activating pyruvate kinase with fructose-1, 6-bisphosphate?