2단원 Biochemistry Test - 在线考试测评模板

Q1:1、학번？

正确答案

Q2:2、이름？

正确答案

Q3:3、Which of the following claims about a particular molecule is correct and gives the correct justification for your answer?

(A) CH4 is a nonpolar molecule because the bonds between carbon and the four hydrogen atoms are polar.

(B) O2 is a polar molecule because the pull on electrons shared between the oxygen atoms is identical.

(C) CO2 is a nonpolar molecule because oxygen exerts greater pull on the shared electrons than does carbon.

(D) H2O is a polar molecule because part of the molecule is partially positively charged while the remaining part is partially negatively charged.

:4、Here is a sketch of two amino acids—the building blocks of polypeptides. When they combine into a dipeptide, certain atoms are removed. Which atoms are removed?[图片]

Q4:

(A) OHO

(B) HOH (正确答案）

(C) NH2

(D) CH3

Q5:5、Isotopes are atoms of a given element that have the same number of protons but vary in the number of neutrons. The element carbon has three isotopes. Carbon-12 accounts for 99% of all carbon in nature. Which of the following is correct about isotopes of carbon?

(A) They are all radioactive.

(B) They contain the same number of neutrons but a different number of protons.

(C) They contain the same number of electrons but are chemically different because the number of neutrons is different.

(D) They are chemically identical because they have the same number of electrons.

:6、Refer to the figure below.[图片]

:How are these two amino acids attached together to form a dipeptide?

Q6:

(A) carbon atom to carbon atom

(B) carbon atom to amino group

(C) amino group to amino group

(D) amino group to carboxyl group

Q7:7、The pH of human blood is normally 7.4. Which of the following correctly explains what that means?

(A) Blood is slightly acidic.

(B) Blood carries more OH− ions than H+ ions.

(C) Blood carries more H+ ions than OH− ions.

(D) Blood pH can fluctuate around 7.4 throughout the day.

Q8:8、Which of the following is stored in the human liver to be used later as a source of energy?

(A) glycine

(B) glycogen

(C) glycerol

(D) glucagon

Q9:9、The molecular formula for glucose is C6H12O6. Which of the following is the molecular formula for an isomer of glucose?

(A) CHO

(B) Cn (H2O)

(C) C12H24O12

(D) C6H12O6

Q10:10、Which of the following pairs of base sequences could form a short stretch of DNA

(A) 5′-TTAA-3′ with 3′-AATT-5′

(B) 5′-ACTG-3′ with 3′-ACTG-5′

(C) 5′-ATTC-3′ with 3′-AUUG-5′

(D) 5′-TTAA-3′ with 5′-AATT-3′