The "pacemaker" of the heart is the
A) sinoatrial node
B) atrioventricular node
C) semilunar valve
D) sinoatrial valve
Answer: A) sinoatrial node
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Biology
- The osmoregulatory/excretory system of a freshwater flatworm is based on the operation of _____.
- Materials are returned to the blood from the filtrate by which of the following processes?
- Excretory organs known as Malpighian tubules are present in _____.
- The production of antibodies
- The end product of thymine degradation is _______.
- All of the following are directly involved in protein turnover except _______.
- Components of the transulfuration pathway include all of the following except _____.
- Homogentisate is an intermediate in the degradation of __________.
- Amino acids whose degradation yields a-ketoglutarate include all of the following except _________.
- Amino acids whose degradation yields succinyl-CoA includes all of the following except ________.
- Which of the following reactions require SAM?
- One type of wax we discussed is used to protect your car. Name that wax
- Amino acids whose degradation yields acetyl-CoA include all of the following except ________.
- All of the following are referred to collectively as the branched chain amino acids except _________.
- The fixation of nitrogen requires _______.
- Asparagine is formed from aspartic acid and _________ .
- The oxidation state of the methenyl group (-CH=) is comparable to that of ____.
- All of the following are directly involved in the synthesis of deoxyribonucleic acid except _______.
- One-carbon carriers in metabolism include
- Extra Question) Which of the following is an a-keto acid/a-amino acid pair used in transamination?
- The conversion of phosphatidylethanolamine to phosphatidylcholine requires ______
- Chorismate is a precursor in the synthesis of all of the following except _______.
- SAM is a methyl donor in the synthesis of ______.
- The tranport of GSH out of cells serves all of the following functions except ______.
- All of the following are purine bases except _____.