Biology 190 Study Guide Quiz

Biological Molecules

• The four major biological molecules are carbohydrates, lipids, proteins, and nucleic acids.

Central Dogma of Molecular Biology

• The Central Dogma outlines the flow of genetic information from DNA to proteins: replication, transcription, and translation.

Origin of Water on Earth

• Water on Earth likely originated from comets, meteorites, and solar winds.
• Additionally, water may have been formed through chemical reactions involving hydrogen and oxygen in the Earth's atmosphere.

Properties of Water

• Water's high surface tension allows it to support life's chemical reactions.
• Water's cohesion and adhesion properties facilitate transport of nutrients and waste in living organisms.
• Water's ability to dissolve a wide variety of substances makes it an ideal medium for chemical reactions.

Rosalind Franklin

• Rosalind Franklin was a British biophysicist and X-ray crystallographer who contributed significantly to the understanding of the structure of DNA.
• Her data and photographs, particularly "Photo 51," were instrumental in James Watson and Francis Crick's development of the double helix model.

Common Elements in Living Organisms

• The six most common elements found in living organisms are carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur.

Modern Definition of a Gene

• A gene is a segment of DNA that codes for a functional product, such as a protein or RNA, and regulates its own expression.

mRNA and tRNA

• mRNA (messenger RNA) carries genetic information from DNA to the ribosome for protein synthesis.
• tRNA (transfer RNA) brings amino acids to the ribosome during protein synthesis, where they are incorporated into a growing protein chain.

Functions of Proteins

• Proteins perform a wide range of functions in living organisms, including:
  • Structural roles (e.g., collagen in skin)
  • Enzymatic roles (e.g., catalyzing chemical reactions)
  • Transport and storage roles (e.g., hemoglobin in blood)
  • Defense and immune system roles (e.g., antibodies)
  • Cell signaling and communication roles