Skip to content


Choose a Chapter below or view the Sitemap

Unit 1:
Ch. 1
Ch. 2
Ch. 3
Interlude A
Unit 2:
Ch. 4
Ch. 5
Ch. 6
Ch. 7
Ch. 8
Ch. 9
Interlude B
Unit 3:
Ch. 10
Ch. 11
Ch. 12
Ch. 13
Ch. 14
Ch. 15
Interlude C
Unit 4:
Ch. 16
Ch. 17
Ch. 18
Ch. 19
Interlude D
Unit 5:
Ch. 20
Ch. 21
Ch. 22
Ch. 23
Ch. 24
Ch. 25
Ch. 26
Ch. 27
Ch. 28
Ch. 29
Ch. 30
Interlude E
Unit 6:
Ch. 31
Ch. 32
Interlude F
Unit 7:
Ch. 33
Ch. 34
Ch. 35
Ch. 36
Ch. 37
Ch. 38
Interlude G

fiogf49gjkf0d
fiogf49gjkf0d
22nd Amino Acid Discovered: Comment from University of Utah
Science, 24 May 2002

The discovery of a 22nd amino acid indicates that life's genetic code is richer than once thought and that scientists may be able to manipulate the code to make new industrial enzymes, University of Utah geneticists say.

» Read the full article

Active Reading Questions

  1. fiogf49gjkf0d
    fiogf49gjkf0d
    Amino acids are the building blocks of
    a) carbohydrates.
    b) fats.
    c) proteins.
    d) nucleic acids.
  2. fiogf49gjkf0d
    fiogf49gjkf0d
    Your book describes 20 amino acids that are biologically active. According to this article, how many genetically encoded amino acids are there?
    a) 20
    b) 21
    c) 22
    d) 26
  3. fiogf49gjkf0d
    fiogf49gjkf0d
    Explain how amino acids are linked to form proteins.
First Name:
Last Name:
Your Email Address:
Your Professor's Email Address:

Chapter Menu

Other Resources

Norton Gradebook

Instructors now have an easy way to collect students’ online quizzes with the Norton Gradebook without flooding their inboxes with e-mails.

Students can track their online quiz scores by setting up their own Student Gradebook.