BIOCHEMISTRY
PRELIMINARY SY. 2023-2024
Lecture/First Semester
INTRODUCTION TO BIOCHEMISTRY
Biochemistry
- Chemistry of life
- Study of life processes, structures, mechanisms,
reactions at the molecular level
- Chemistry, Biology, & Genetics
Vitalism Theory
- Idea that substances and processes associated
with living organisms did not behave according
to the known laws of physics and chemistry
- Organic vs. Inorganic
Evidences for Vitalism
- Only living things have a high degree of
complexity
- Only living things extract, transform and utilize
energy from their environment
- Only living things are capable of self assembly
and self replication
Origins of Biochemistry: a challenge to vitalism and…
Famous Dead Scientists
1. Friedrich Wohler (19th century)
-Synthesized urea from inorganic
substance—ammonium cyanate.
2. Eduard Buchner and Hans Buchner (1897)
-found that glucose + dead yeast cells are
still able to undergo fermentation,
demonstrating that reactions can occur in
vitro.
3. Emil Fischer (1894)
- Each enzyme can only catalyze specific
complex molecules called substrates.
- proposed the lock and key theory, which
states that enzymes have a specific
shape that directly correlates to the shape
of the substrate.
4. James Batcheller Sumner
- studied the enzyme urease, which breaks
down urea into ammonia and carbon
dioxide
- An enzyme is protein
5. Gregor Mendel (mid-1900)
- Started describing genes.
- Father of Genetics
6. Oswald Avery, Colin McLeod, Maclyn McCarty
(1944)
- identified DNA as information molecules
7. James Watson (still alive) and Francis Crick
(1953)
- proposed the structure of the DNA
- In 1958 Crick proposed the central
dogma of biology
Central Dogma
- Flow of information
- DNA -> RNA (mRNA) -> Protein
- Replication -> Transcription -> Translation
Areas of Biochemistry
- Biomolecules. Structure and function of biological
macromolecules
- Metabolism
- Catabolism: Destructive phase
- Complex substance to subunits
(simpler substance)
- Anabolism: Constructive phase
- From simpler substance to
complex substance
- Molecular Genetics
- How life is replicated
- Regulation of protein synthesis
Objective of Biochemistry
- determine how the collections of inanimate
molecules that constitute living organisms interact
with each other to maintain and perpetuate life
Scope of Biochemistry
- LIFE. chemistry of living matter in its different
phases of activity, from the smallest
microorganisms such as viruses to the most
complex ones as human
- Virus: has either DNA or RNA
- Cell: has both DNA and RNA
Chemical Reactions Occurring in Living Organism
Oxidation
- gains oxygen or loses hydrogen/electron
⇀aerobic oxidation – takes place in the
presence of oxygen
⇀anaerobic oxidation – occurs in the
absence of oxygen
