Transcript Chapt02 Lecture 13ed Pt 1

Human Biology
Sylvia S. Mader
Michael Windelspecht
Chapter 2
Chemistry of
Life
Lecture Outline
Part 1
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1
Chemistry of Life
2
Points to ponder
• How are living things organized from atoms to
molecules?
• What is pH and how is it important to living
organisms?
• What are the four macromolecules found in living
organisms?
• What are the structure (subunits) and function of
these four macromolecules?
• How are proteins organized and how is their shape
important to their function?
• How are DNA and RNA similar and how are they
different?
3
2.1 From Atoms to Molecules
Building blocks from large to small
• ______ is anything that has mass and takes up
space.
• Elements are the basic building blocks of matter
that _____ be broken down by chemical means.
• _____ are the smallest units of an element that
retain the element’s physical and chemical
properties. These bond together to form
________.
4
2.1 From Atoms to Molecules
• Atomic symbol
• Atomic mass
• Atomic number
Periods
1
2
3
4
Figure 2.1 A portion of the
periodic table of elements.
Elements
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I
VIII
1
atomic number
H
atomic symbol
2
atomic mass
He
1.008
II
III
IV
V
VI
VII
4.003
3
4
5
6
7
8
9
10
Li
Be
B
C
N
O
F
Ne
6.941
9.012
10.81
12.01
14.01
16.00
19.00
20.18
11
12
13
14
15
16
17
18
Na
Mg
Al
Si
P
S
Cl
Ar
22.99
24.31
26.98
28.09
30.97
32.07
35.45
39.95
19
20
31
32
33
34
35
36
K
Ca
Ga
Ge
As
Se
Br
Kr
39.10
40.08
69.72
72.59
74.92
78.96
79.90
83.60
Groups
5
2.1 From Atoms to Molecules
Subatomic particles of atoms
• Neutrons are ______ (uncharged).
• Protons are _________ charged.
• Neutrons and protons make up the ________.
• Electrons are __________ charged and orbit
around the _________.
6
2.1 From Atoms to Molecules
Subatomic particles of atoms
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Subatomic Particles
Particle
Charge
Atomic Mass Unit
(AMU)
Proton
+1
1
Neutron
0
1
Electron
–1
0
1p
hydrogen
H
Figure 2.2 The
atomic structure
of select
elements.
6p
6n
7p
7n
8p
8n
carbon
C
nitrogen
N
oxygen
O
2.1 From Atoms to Molecules
Isotopes
• _________ are atoms that have the same atomic
number but a different atomic mass because the
number of neutrons differ.
• _____________ are useful in dating
old objects, imaging body organs
and tissues through X-rays, and
killing cancer cells.
• Radiation can be harmful by
damaging cells and DNA and/or
causing cancer.
8
2.1 From Atoms to Molecules
Isotopes
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missing
portion
of organ
larynx
thyroid gland
trachea
a.
b.
a: © Biomed Commun./Custom Medical Stock Photo; b (patient): Courtesy National Institutes of Health;
(brain scan): © Mazzlota et al./Photo Researchers, Inc.
Figure 2.3 Medical uses for
low-level radiation.
2.1 From Atoms to Molecules
Molecules
• Made of atoms that are _______ together
• Can be made of the _______ atom or
______________ atoms
10
2.1 From Atoms to Molecules
Ionic bonds
• Atoms in this type of bond donate or take on
electrons
• Result in a stable ____________
• Occur between particles that are charged
(ions)
11
2.1 From Atoms to Molecules
Ionic bonds
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Na
Cl
sodium atom (Na)
chlorine atom (Cl)
–
+
Na
Cl
sodium ion (Na+)
chloride ion (Cl–)
Na+ Cl–
sodium chloride (NaCl)
a.
b.
b(crystals, shaker): © Evelyn Jo Johnson
Figure 2.5 Formation of an ionic bond.
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2.1 From Atoms to Molecules
Covalent bonds
• Atoms in this type of bond _______ electrons
• Result in a stable ______________
13
2.1 From Atoms to Molecules
Covalent bonds
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
1p
8p
8n
1p
+
8p
8n
1p
oxygen
O
2 hydrogen
2H
1p
water
H2O
a. When an oxygen and two hydrogen atoms covalently bond, water results.
8p
8n
oxygen
O2
+
8p
8n
oxygen
O2
8p
8n
8p
8n
oxygen gas
O2
b. When two oxygen atoms covalently bond, oxygen gas results.
Figure 2.6 Covalent bonds.
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