Biology

• Ailments of the nervous system

  • Alzheimer's Disease
  • Cerebral Palsy
  • Epilepsy
  • Multiple Sclerosis
  • Parkinson's Disease
• Alzheimer's Disease


  Most common type of dementia. A brain disorder that slowly destroys memory and thinking skills and eventually the ability to carry out the simplest tasks. There is no cure for Alzheimer's other than just focusing on the patient's quality of life.
• Cerebral Palsy


  Caused by infection or damage to the brain before, during, or immediately after birth. It's associated with neurological and mental problems. Symptoms include impaired sensations and intelligence, loss of balance, and paralysis. Treatments include medications and surgery than can help improve patient's skills and ability to communicate with the world.
• Epilepsy


  A neurological disorder that typically causes seizures due to faulty electrical impulses in the brain. Symptoms include uncontrollable jerking movements, temporary confusion, and black staring spells. Seizures may become so violent that it causes bodily harm. Treatments include medication, vagus nerve stimulation, or surgery.
• Multiple Sclerosis


  Due to damaged protective myelin sheath surrounding nerves in the brain and spinal cord. Results in the disruption in communication between the CNS and the PNS. Symptoms include blurred vision, speech defects, unsteady walking, and shaky movements of the limbs. Treatments include medication and physical therapy to lessen the symptoms.
• Parkinson's Disease


  A degenerative disease that affects the basal ganglia of the brain. Associated with a deficiency in the neurotransmitter dopamine. Symptoms include trembling of hands, slowed movements, expressionless unmodulated voice, and memory loss. Treatments include medication, physical therapy, and surgery that can only lessen the symptoms.
• To care for the nervous system

  • Proper nutrition
  • Adequate sleep and rest
  • Regular exercise
  • Plenty of water
  • Avoiding drug and alcohol abuse
  • Undergoing immunization
• Charles Darwin (1866) proposed the "theory of evolution" in his book or simple "On the Origin of Species". He proposed the "survival of the fittest" hypothesis and he only observed the pattern of evolution.
• Johann Friedrich Miescher (1869) isolated "nuclein" in the nuclei of human white blood cells, which would later be renamed "deoxyribonucleic acid (DNA)".
• Albrecht Kossel (1885 – 1901) discovered a fibrous structure in the nucleus of cells, which he named "chromatin". He observed how chromosomes separate during cell division or "mitosis". He was unaware of Mendel's laws which did not make him the connection between his observations and genetic inheritance.
• Walter Sutton and Theodore Boveri (1902 – 1903) independently developed the "chromosome theory of inheritance". This helped explain the inheritance patterns Gregor Mendel had observed over a century before. Walter Sutton studied grasshopper chromosomes while Theodore Boveri studied roundworm embryos.
• Chromosomal Theory of Inheritance

  The idea that the genetic material passed down from parent to child is within the chromosomes. Chromosomes contain the genetic material, and they are passed along from parent to offspring. They are found in pairs in the nucleus of most cells. These separate during the formation of sperm and egg cells in men and women, where each parent contributes one set of chromosomes to its offspring.
• Erwin Chargaff (1950) discovers that DNA composition is species specific. Chargaff's rules include: # of guanine units = # of cytosine units, # of adenine units = # of thymine units.
• Rosalind Franklin (1952) through X-ray diffraction, she was able to produce two sets of high-resolution photographs of DNA fibers. She thought that the DNA molecule probably has a helical structure. She came close to discovering the structure of DNA yet was beaten by Thomas Watson and Francis Crick.
• James Watson and Francis Crick (1953) using the photographs by Franklin, they were able to solve the mystery of the structure of DNA which is double helical. Along with "Maurice Wilkin"", they were awarded the "Nobel Prize for Physiology and Medicine" in 1962. Sadly, Franklin wasn't honored for her contribution in the discovery because of the rules of being awarded one: Only living people can be awarded the Nobel Prize, and only 3 people (Watson, Crick, and Wilkin) can be awarded too.
• DNA (Deoxyribonucleic acid)


  The nucleic acid that contains the genetic code of organisms. It's most often considered the "blueprint" of life. Its functions include heredity, gene expression, and mutation. Its features include double helix structure, anti-parallel strands, and complementary base pairing.
• RNA (Ribonucleic acid)


  A nucleic acid responsible for transmitting genetic information and facilitating protein synthesis within cells. It is single stranded and has nitrogenous bases like adenine, uracil, cytosine, and guanine. Its functions include facilitating the translation of DNA into proteins and serving as a messenger between DNA and ribosomes. Its structure includes a sugar backbone (ribose), nitrogenous bases, and phosphate groups. There are 3 types: tRNA, rRNA, and mRNA.
• Central Dogma of Molecular Biology

  1. DNA Replication

  2. RNA Transcription

  3. Protein Translation
• DNA Replication


  1. Initiation

  2. Elongation

  3. Termination
• RNA Transcription


  1. Initiation

  2. Elongation

  3. Termination
• Protein Translation


  1. tRNA Charging

  2. Initiation

  3. Elongation

  4. Termination
• Transcription


  1. RNA polymerase binds to promoter sequence

  2. Separates DNA strands

  3. Uses template strand (3' to 5') as template

  4. Synthesizes complementary RNA molecule
• Template strand


  DNA strand that goes from 3' to 5', used as template for transcription
• Coding strand


  Unused DNA strand, alike to synthesized RNA molecule
• Transcription - Elongation


  1. Ribonucleotides added to template

  2. RNA polymerase reads template one base at a time

  3. Builds complementary RNA molecule
• Transcription - Termination


  1. RNA polymerase encounters terminator sequence

  2. Transcription stops

  3. RNA transcript released from RNA polymerase
• Protein Translation


  1. tRNA Charging (amino acid attachment)

  2. Initiation (start codon, small ribosome subunit binds)

  3. Elongation (polypeptide chain grows as per mRNA codons)

  4. Termination (stop codon reached, polypeptide chain released)
• Protein


  • Large complex molecules that play many critical roles in the body
  • Made up of smaller units called "amino acids"
  • 9 essential amino acids can't be synthesized by the body naturally
• Enzyme


  • Biomolecule that speeds up biochemical reactions
  • Names end with "-ase"
• Enzymes in DNA replication

  • Helicase
  • DNA Polymerase
  • Primase
  • Ligase
• Table of codons
• Mutation


  • Stable and heritable changes in the genetic material
  • Changes in nitrogen base sequence causing mistakes in transcription and translation
• Causes of mutations


  • Spontaneity/By chance
  • Mutagens (radiation, chemicals, infectious agents)
• Types of mutations


  • Point Mutations (substitution, missense, nonsense)
  • Frameshift Mutations (insertion, deletion)
  • Chromosomal Mutations (deletion, duplication, inversion, translocation)
• Diseases linked to point mutations include albinism and sickle cell anemia
• Diseases linked to frameshift mutations include beta thalassemia and cystic fibrosis
• Genetic Engineering/DNA Technology


  • Techniques to study, improve, create, and manipulate genetic material
  • Involves molecular techniques like DNA extraction, gene amplification, gene isolation, gene identification, and gene mapping
• Recombinant DNA Technology


  Using restriction enzymes and DNA ligase to cut and insert genes of interest into vectors, which are then used to genetically modify organisms
• Applications of Genetic Engineering

  • Medicine (newborn screening, gene therapy, immunization)
  • Agriculture (transferring beneficial genes to crops and livestock)
  • Forensics (DNA evidence)
• Alzheimer's Disease


  Most common type of dementia. A brain disorder that slowly destroys memory and thinking skills and eventually the ability to carry out the simplest tasks. There is no cure for Alzheimer's other than just focusing on the patient's quality of life.