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Chapter 4 ENZYMES AND ENERGY

When the relationship between substrate concentration and reaction rate reaches a plateau of maximum velocity, the enzyme is said to be ______________.

When the relationship between substrate concentration and reaction rate reaches a plateau of maximum velocity, the enzyme is said to be saturated.

Another term for enzyme is

Another term for enzyme is biological catalyst

Which two enzymes function in the most similar environments?

Which two enzymes function in the most similar environments Which two enzymes function in the most similar environments? Salivary amylase and trypsin.

Where in the body would you expect to find the enzyme Pepsin?

Where in the body would you expect to find the enzyme Pepsin? stomach

During an enzyme-catalyzed reaction, the substrate binds to the enzyme’s __________________ _______________.

During an enzyme-catalyzed reaction, the substrate binds to the enzyme’s active site.

A _______________ enzyme adds a phosphate group.

A kinase_____ enzyme adds a phosphate group.

When the relationship between substrate concentration and reaction rate reaches a plateau of maximum velocity, the enzyme is said to be ______________.

When the relationship between substrate concentration and reaction rate reaches a plateau of maximum velocity, the enzyme is said to be saturated.

CH 4 and 5 What is the effect of carbon dioxide on the blood pH?

CH 4 and 5 What is the effect of carbon dioxide on the blood pH? Lowers pH

Table 4.3

State the reversible reaction that stabilizes blood pH.

State the reversible reaction that stabilizes blood pH. HCO3- + H+ ⇄ HCO3- Bicarbonate ion picks up free H+ (a strong acid) and converts it to carbonic acid, (HCO3- , a weaker acid). The direction in which the reaction goes depends on the concentration of ions on each side (Law of Mass Action)

CH 4 and 5 What is an enzyme? How are enzymes named?

CH 4 and 5 What is an enzyme? How are enzymes named? An enzyme is a biological catalyst and speeds up the rate of a chemical reaction without itself being used up in the reaction. How are enzymes named? They end in –ase They begin with a word root that names their function Older enzymes, such as pepsin, a stomach protease, are not named in this way, but you still have to know them.

CH 4 and 5 What do we mean when we say that an enzyme acts by lowering the activation energy of a reaction?

What do we mean when we say that an enzyme acts by lowering the activation energy of a reaction? Activation energy is the energy required to start a reaction. Therefore, enzyme-catalyzed reactions go much faster than without the enzyme present.

Different diseased organs can liberate different isoenzymatic forms of an enzyme into the blood, aiding the diagnosis of disease. Creatine phosphokinase (CPK or CK) is normally located in the cytosol and catalyzes the formation of ATP from phosphocreatine. Different isoenzymes of CK are released from different organs when these organs are damaged. When the CK-MB isoform is found in blood, it helps to diagnose which condition?

Different diseased organs can liberate different isoenzymatic forms of an enzyme into the blood, aiding the diagnosis of disease. Creatine phosphokinase (CPK or CK) is normally located in the cytosol and catalyzes the formation of ATP from phosphocreatine. Different isoenzymes of CK are released from different organs when these organs are damaged. When the CK-MB isoform is found in blood, it helps to diagnose which condition? Myocardial infarction. See p. 92 “Clinical Application”

An inborn error of metabolism, such as ________________, is due to a defective enzyme which normally converts phenylalanine into tyrosine. The disease is inherited as an autosomal recessive trait.

An inborn error of metabolism, such as phenylketonuria (PKU) , is due to a defective enzyme which normally converts phenylalanine into tyrosine. The disease is inherited as an autosomal recessive trait.

Table 4.4

During an enzyme-catalyzed reaction, the substrate binds to the enzyme’s __________________ _______________.

During an enzyme-catalyzed reaction, the substrate binds to the enzyme’s active site.