68 Chapter 4
Fats Glucose^ Amino acids^Glycogen(^)
(^)
(Hydrolysis) (Deamination)
Glucose- 6 - PO 4
Liver (^)
(^) Glycerol NH 3 (Ammonia) (^)
Pyruvic acid
Ketoacid
Fatty acids^
( -oxidation) (^) CO Lactic acid^
2 Urea^
(Ketogenesis) Acetyl-CoA (^)
liver (^)
Ketones (^)
(^) Citric (^)
acid (^)
cycle
½O 2
e–
(^)
CO^2 (Electron transportsystem)^
H+
(^) H 2 O (^)
(^)
ADP ATP (^)
(^) ®
Learning
Cengage ©
Figure 4- 4 How the digestion of proteins and fats fits into the biochemical respiration
process.
that piece of candy into your mouth during class break to
get some extra energy to finish class, you now will have a
better understanding of how that carbohydrate is con-verted
to ATP (Figure 4-5), the fuel that runs our cells. The
simplest way of describing cellular or biochemical
respiration is to begin the process with a glucose mol-ecule
(Figure 4-6). Glycolysis occurs in the cytoplasm of the cell
and produces pyruvic acid. If oxygen is available, the
pyruvic acid is eventually converted to acetyl-CoA, which
then enters the citric acid cycle, eventually being converted
to CO 2 , H 2 O, and 38 ATP. If oxygen is not avail-able, the
pyruvic acid is converted to lactic acid and only two ATP
molecules are produced.
Summary of ATP Production
from One Glucose Molecule
Table 4-1 summarizes products produced and the total ATP
produced in the individual stages of the cellular me-
tabolism of one glucose molecule. The stages are broken
down into glycolysis, acetyl-CoA production, and the
citric- acid cycle.
Introduction to Cellular
Reproduction
Cellular reproduction is the process by which a sin-gle cell
duplicates itself. In this process, the genetic -material in the
nucleus is duplicated during interphase of the cell cycle
followed by the process called mitosis (my-TOH-sis)
when the nuclear material is replicated. This is followed by
duplication of the cellular organelles in the cytoplasm
called cytokinesis (sigh-toh-kye-NEE-sis), which is the
final event of mitosis leading to two new daughter cells.
These processes, part of the cell cycle, allow our bodies to
grow, repair themselves, and main-tain our structures and
functions. In other words, these -processes allow us to
maintain our life.
However, cellular reproduction is also the process by
which our genetic material is passed on to our off-spring
from one generation to the next. In this process of cellular
reproduction, special cells called sex cells, the egg and the
sperm, are produced. In this type of cellu-lar reproduction,
the genetic material must not only be duplicated, but it
must also be reduced in half so that the female egg carries
half of the genetic material or