Biochemistry and Life Overview

Biochemistry and Life

• Biochemistry is the chemistry of life
• Biochemistry combines biology and chemistry
• All living organisms use the same types of biomolecules and energy, regardless of complexity
• Biochemistry can describe life processes
• Disciplines such as physics can inform biochemistry by providing tools and data
• Example: magnetic resonance imaging (MRI) is a tool originally developed in physics, that is now an important part of biochemistry and the health sciences

Origin of Life on Earth

• The origin of life on earth is a topic of interest
• Biochemistry helps to explain how living organisms arise from non-living matter

Amino Acids

• Amino acids are organic compounds that contain an amino group and a carboxyl group
• Twenty different amino acids form the building blocks of proteins

Carbohydrates

• Carbohydrates are the primary energy source for most living organisms
• Carbohydrates can also be used in structural components of cells
• Carbohydrates are composed of carbon, hydrogen, and oxygen
• Common types of carbohydrates include sugars, starches, and cellulose

Nucleotides

• Nucleotides are the building blocks of nucleic acids such as DNA and RNA
• Nucleotides are composed of a sugar, a phosphate group, and a nitrogenous base
• DNA carries genetic information, while RNA translates genetic info into proteins

Lipids

• Lipids are a diverse group of molecules that are generally insoluble in water
• Lipids include fats, oils, waxes, sterols, and phospholipids
• Important functions of lipids include energy storage and cell membrane formation

Functional Groups Important in Biochemistry

• Functional Groups are specific groups of atoms within molecules that have characteristic properties
• Important functional groups in biochemistry include:
  • Hydroxyl group (-OH)
  • Amino group (-NH2)
  • Carboxyl group (-COOH)
  • Phosphate group (-PO4^3-)

The Earth and Its Age

• The Earth is about 4.5 billion years old
• The earliest evidence of life on Earth dates back to about 3.8 billion years ago.
• Living organisms have constantly changed over time due to evolution

Biomolecules

• Biomolecules are large molecules that are essential for life
• Biomolecules are made up of smaller molecules called monomers that join to form polymers
• Biomolecules are classified into four major categories: carbohydrates, lipids, proteins, and nucleic acids

Molecules to Cells

• The simplest living organisms are single-celled organisms
• Cells are the basic unit of life
• Cells are made up of many different biomolecules that work together
• Cells are organized into tissues, organs, and organ systems
• Cells carry out all the functions required for life, including energy production, growth, and reproduction.

Prokaryotes and Eukaryotes

• Prokaryotes and eukaryotes are the two main types of cells
• Prokaryotes lack a nucleus and other membrane-bound organelles
• Eukaryotes have a nucleus and other membrane-bound organelles
• The difference between prokaryotes and eukaryotes is the biggest distinction in the biological world

Prokaryotic Cells

• Prokaryotes are simpler and typically smaller than eukaryotic cells
• Prokaryotes include bacteria and archaea
• Prokaryotes have a cell wall, a plasma membrane, cytoplasm, and ribosomes
• Some prokaryotes can perform photosynthesis or chemosynthesis to generate energy

Eukaryotic Cells

• Eukaryotes have a more complex structure than prokaryotes
• Eukaryotes have a nucleus, where the genetic material DNA is stored
• Other membrane-bound organelles include the endoplasmic reticulum, Golgi apparatus, mitochondria, and chloroplasts
• Eukaryotes include all plants, animals, fungi, and protists

Five-Kingdom Classification System

• The Five-Kingdom Classification System classifies all living organisms into five kingdoms:
  • Monera (bacteria)
  • Protista (single-celled eukaryotes)
  • Fungi
  • Plantae (plants)
  • Animalia (animals)

Three-Domain Classification System

• The Three-Domain Classification System is a more recent classification system
• The Three-Domain Classification System divides living organisms into three domains:
  • Bacteria
  • Archaea
  • Eukarya
• Archaea are prokaryotes that have distinct evolutionary relationships with bacteria and eukaryotes
• The Three-Domain Classification System reflects the evolutionary relationships of organisms more accurately than the Five-Kingdom Classification System

Eukaryotic Origins

• Eukaryotic cells likely evolved from prokaryotic cells
• The endosymbiotic theory proposes that mitochondria and chloroplasts originated from prokaryotic cells that were engulfed by larger cells
• The evolution of eukaryotic cells led to the diversification of life on Earth

Biochemical Energetics

• Biochemical energetics is the study of energy flow in living organisms
• All living organisms require energy to maintain life processes
• Energy metabolism is the sum of all chemical reactions that occur in an organism
• Energy transformations in living organisms are governed by the laws of thermodynamics

Thermodynamic Principles

• Thermodynamics is the study of energy and its transformations
• The first law of thermodynamics states that energy can be neither created nor destroyed, only converted from one form to another
• The second law of thermodynamics states that the entropy of a closed system always increases over time
• Entropy is a measure of disorder or randomness

Energy Changes

• Living organisms exchange energy with their surroundings
• Organisms can convert energy from one form to another, but they cannot create or destroy energy
• Energy transformations often involve changes in enthalpy and entropy

Spontaneity in Biochemical Reactions

• Some biochemical reactions occur spontaneously, meaning they release energy
• Other biochemical reactions require an input of energy to occur
• The change in free energy (Delta G) is a measure of the spontaneity of a reaction
• A negative Delta G indicates a spontaneous reaction
• A positive Delta G indicates a non-spontaneous reaction

Life and Thermodynamics

• Living organisms are open systems, meaning they exchange energy and matter with their surroundings
• Living organisms maintain a state of low entropy through a constant input of energy
• Living organisms use energy to create and maintain order within their cells and bodies

Predicting Reactions

• By understanding the laws of thermodynamics, we can predict whether a given biochemical reaction will be spontaneous or non-spontaneous
• This knowledge can be used to design experiments and understand how organisms function at the molecular level

Explore the fascinating world of biochemistry and its crucial role in understanding life processes. This quiz covers the origin of life on Earth, the structure and function of amino acids, and the importance of carbohydrates as energy sources. Test your knowledge on how these elements interact within living organisms.