Biomedical Engineering Reference
In-Depth Information
TABLE 3.1
The Genetic Code
First Base
Second Base
Third Base
A
U
G
C
A
Lys
Ile
Arg
Thr
A
Lys
Met - Start
Arg
Thr
G
Asn
Ile
Ser
Thr
U
Asn
Ile
Ser
Thr
C
U
Stop
Leu
Stop
Ser
A
Stop
Leu
Trp
Ser
G
Tyr
Phe
Cys
Ser
U
Tyr
Phe
Cys
Ser
C
G
Glu
Val
Gly
Ala
A
Glu
Val
Gly
Ala
G
Asp
Val
Gly
Ala
U
Asp
Val
Gly
Ala
C
C
Gln
Leu
Arg
Pro
A
Gln
Leu
Arg
Pro
G
His
Leu
Arg
Pro
U
His
Leu
Arg
Pro
C
Amino acid 3-letter and 1-letter codes: Ala (A)
¼
Alanine; Arg (R)
¼
Arginine; Asn (N)
¼
Asparagine; Asp (D)
¼
Aspartic acid;
Cys (C)
¼
Cysteine; Glu (E)
¼
Glutamic acid; Gln (Q)
¼
Glutamine; Gly (G)
¼
Glycine; His (H)
¼
Histidine; Ile (I)
¼
Isoleucine;
Leu (L)
¼
Leucine; Lys (K)
¼
Lysine; Met (M)
¼
Methionine; Phe (F)
¼
Phenylalanine; Pro (P)
¼
Proline; Ser (S)
¼
Serine; Thr
(T)
¼
Threonine; Trp (W)
¼
Tryptophan; Tyr (Y)
¼
Tyrosine; Val (V)
¼
Valine.
3.3 TISSUES
Groups of cells and surrounding substances that function together to perform one or more
specialized activities are called tissues (Figure 3.16). The four primary types of tissue in the
human body are epithelial, connective, muscle, and nervous. Epithelial tissues are either
composed of cells arranged in sheets that are one or more layers thick or are organized into
glands that are adapted for secretion. They are also characterized by having a free surface—
for example, the inside surface of the intestines or the outside of the skin—and a basilar mem-
brane. Typical functions of epithelial tissue include absorption (lining of the small intestine),
secretion (glands), transport (kidney tubules), excretion (sweat glands), protection (skin,
Figure 3.16a), and sensory reception (taste buds). Connective tissues are the most abundant
and widely distributed. Connective tissue proper can be loose (loosely woven fibers found
around and between organs), irregularly dense (protective capsules around organs), and reg-
ularly dense (ligaments and tendons), whereas specialized connective tissue includes blood
