Biochemistry _ CH-1.pdf biochemistry for

Biochem

1. Paul D. Adams • University of Arkansas
cengage.com/chemistry/campbell
Chapter One
Biochemistry and the
Organization of Cells

2. Chapter Outline
1-1 Basic Themes
1-2 Chemical Foundations of Biochemistry
1-3 The Beginnings of Biology: Origin of Life
1-4 The Biggest Biological Distinction—Prokaryotes
and Eukaryotes
1-5 Prokaryotic Cells
1-6 Eukaryotic Cells
1-7 How We Classify Eukaryotes and Prokaryotes
1-8 Biochemical Energetics
1-9 Energy and Change
1-10 Spontaneity in Biochemical Reactions
1-11 Life and Thermodynamics

3. Basic Themes
•All living things make use of the same types of biomolecules,
and all use energy. As a result, all living things can be
studied using the methods of chemistry and physics
•The fundamental similarity of cells of all types makes it
interesting to speculate on the origins of life
•both cells and the biomolecules of which they are made
must have arisen ultimately from very simple molecules,
such as H
2O, CH
4, CO
2, NH
3, N
2, and H
2
• Field of Biochemistry draws many disciplines
• allows us to answer questions related to molecular
nature of life

4. Levels of
Structural
Organization
in the Human
Body

5. Chemical Foundations of Biochemistry
•Organic chemistry:the study of the compounds of
carbon
•the cellular apparatus of living organisms is made up
of carbon compounds
•biomolecules are part of the subject matter of organic
chemistry
•the reactions of biomolecules can be described by the
methods of organic chemistry
•The experiment of Friedrich Wöhlerin 1828

6. Biomolecules
(Cont’d)
•Functional
group:an atom or
group of atoms
that show
characteristic
physical and
chemical
properties

7. ATP and the Reactions for its Formation

8. ATP and the Reactions for its Formation

9. ATP and the Reactions for its Formation

10. The Beginnings of Biology: Origins of Life
•The “big bang”theory
•all matter was originally confined in a very small space
•as the result of an explosion, it started to expand with great
force; temperature approx. 15 x 10
9
K
•the average temperature of the universe has been decreasing
ever since
•in the earliest stages of the universe, the only elements present
were H, He, and Li
•other elements formed by
•thermonuclear reactions in stars
•explosions of stars
•the action of cosmic rays outside the stars

11. Relative Abundance of Important Elements

12. Biomolecules
•Gases present in the atmosphere of the early earth included
NH
3, H
2S, CO, CO
2, CH
4, N
2, H
2, and H
2O
•Experiments have demonstrated that important biomolecules,
such as proteins and nucleic acids, could have arisen under
abiotic (nonliving) conditions from reactions of these simple
compounds
•in the earth’s oceans
•on the surface of clay particles

13. Biomolecules (Cont’d)
•Living cells include very large molecules, such as proteins,
nucleic acids, polysaccharides, and lipids
•these biomolecules are polymers (Greek: poly+ meros, many +
parts)
•they are derived from monomers (Greek: mono+ meros, single +
part)
--amino acids → proteins
--nucleotides → nucleic acids
--monosaccharides → polysaccharides
--glycerol and 3 fatty acids → lipids
• Proteins and Nucleic Acids play a role in life processes.

14. Informational Macromolecules

15. Directionality in Macromolecules

16. Directionality in Macromolecules

17. Directionality in Macromolecules

18. Biomolecules (Cont’d)
•Enzymes:a class of proteins that display catalytic activity.
•the catalytic effectiveness of a given enzyme depends on its
amino acid sequence
•Genetic code:the relationship between the nucleotide
sequence in nucleic acids and the amino acid sequence in
proteins
•theories of the origin of life consider how such a coding system
might have arisen

19. Molecules to Cells: Biomolecules
(Cont’d)
•Which came first…the chicken
or the egg?
•catalytic activity associated
with proteins
•coding associated with
nucleic acids
• It has been discovered recently
that certain types of RNA have
catalytic activity and are
capable of catalyzing their own
further processing RNA is now
considered by many scientists
to have been the original
coding material
•it still serves this function in
some viruses

20. The “RNA World”
•The appearance of a form of RNA capable of coding
for its own replication was the pivotal point in the
origin of life
•This original RNA both encoded for and catalyzed its
own replication
•In time, this system evolved to encode for the
synthesis of protein catalysts
•Even later, DNA became the primary genetic
material, and RNA took on only an intermediary role
in the synthesis of proteins

21. Stages in the Evolution of Self-replicating RNA Molecules

22. Molecules to Cells: Biomolecules (Cont’d)
•A key point in the development of living cells is the
formation of membranes that separate cells from their
environment
•Some theories of the origin of life focus on proteins
•according to one model, proteinoids aggregated to
form microspheres
•Double-Origin theory:the development of a coding
system and the development of catalysis came about
separately
•a combination of the two later in time produced life as
we know it.

23. Molecules to Cells: Biomolecules (Cont’d)
The Vital Importance of a cell membrane in the origin of
Life

24. Molecules to Cells: Biomolecules (Cont’d)
Replication and Reproduction

25. Molecules to Cells: Biomolecules (Cont’d)
From Membrane-Coated RNA to Bacteria

26. Molecules to Cells: Biomolecules (Cont’d)
From Membrane-Coated RNA to Bacteria

27. The Biggest Biological Distinction-Prokaryotes
and Eukaryotes
•Prokaryote:Greek derivation meaning “before the
nucleus”
•single-celled organisms
•include bacteria and cyanobacteria
•Eukaryote:Greek derivation meaning “true nucleus”
•contain a well-defined nucleus surrounded by a
nuclear membrane
•can be single celled, such as yeasts and Paramecium,
or multicellular, such as animals and plants

28. Comparison of Prokaryotes and Eukaryotes

30. Summary of Organelles and their Function(s)

31. How Doe We Classify Living Organisms
Today?
•5-kingdom system takes into account differences
between prokaryotes and eukaryotes
•Provides classification for eukaryotes that are neither
plants nor animals
•Kingdoms are: Monera, Protista, Fungi, Plantae, and
Anamilia

32. Five Kingdoms, Three Domains

33. Biochemical Energetics
• All cells require energy to functions
• Light from the sun is the ultimate source of energy for
all life on earth
•photosynthetic organisms use light energy to drive the
energy-requiring synthesis of carbohydrates
•non-photosynthetic organisms consume these
carbohydrates and use them as energy sources
• The energetics of a chemical reaction
•if the change in free energy is negative (free energy
decreases), the reaction is spontaneous as written
•if the change in positive (free energy increases), the
reaction will not occur as written unless energy is
supplied from an external source

34. How are energy changes measured?
Thermodynamics-branch of science that answers questions
about processes that are energetically favorable

35. Energy and Change, Spontaneity in
biochemical reactions
• Spontaneousmeans “fast”
• Free Energy of a System
G < 0 spontaneous exergonic-energy released
G = 0 Equilibrium
G > 0 Nonspontaneous endergonic-energy required
• Life and Thermodynamics
G = H -TS
H is heat of a reaction at constant pressure
S is the change in entropy
G is the change in free energy
•T is the temperature