Genes & Health

• What increases the rate of gas exchange by diffusion?

  Increased surface area, decreased distance, steeper gradient
• What does Fick's Law state about diffusion?

  Larger area, higher concentration, shorter distance increases rate

  
• How are mammal lungs adapted for rapid gas exchange?

  Large surface area, good blood supply, short diffusion distance
• Why is a good blood supply important for gas exchange in lungs?

  It maintains a steep concentration gradient
• What is the thickness of alveoli in mammal lungs?

  One cell thick
• What are the main components of the cell membrane?

  • Phospholipid bilayer
  • Proteins (transport, receptor, enzymes, structural, recognition)
• What is the main function of the cell membrane?

  Controls movement of substances in and out
• What model describes the structure of the cell membrane?

  The fluid mosaic model
• What factors affect the movement of molecules through the cell membrane?

  Properties of the molecule and cell requirements
• What are the types of movement through the cell membrane?

  • Diffusion
  • Facilitated diffusion
  • Osmosis
  • Active transport
  • Endocytosis/Exocytosis
• What is diffusion?

  Passive movement of small, non-polar molecules
• How does the rate of gas exchange by diffusion increase?

  Increased surface area, decreased distance, steeper gradient
• What is facilitated diffusion?

  Transport via channel proteins for polar molecules
• What is osmosis?

  Movement of water from low to high solute concentration
• What is active transport?

  Transport against concentration gradient using energy
• What provides energy for active transport?

  Hydrolysis of ATP
• What is endocytosis?

  Transport of large particles into the cell
• What is exocytosis?

  Transport of large particles out of the cell
• What are the components of a mononucleotide?

  • Bases: adenine, guanine, cytosine, thymine
  • Sugar: deoxyribose
  • Phosphate group

  
• What are the base pairing rules in DNA?

  A pairs with T, C pairs with G
• What type of bonds hold the DNA structure together?

  Hydrogen bonds and phosphodiester bonds
• What is the structure of DNA?

  Double-stranded alpha double helix
• What are the components of mRNA?

  • Bases: adenine, guanine, cytosine, uracil
  • Sugar: ribose
  • Structure: single-stranded
• What is the function of tRNA?

  Carries anticodons complementary to mRNA codons

  
• What are the stages of protein synthesis?

  1. Transcription in the nucleus
  2. Translation at the ribosomes
• What happens during transcription?

  DNA is transcribed into mRNA in the nucleus
• What is the role of RNA polymerase in transcription?

  Catalyzes the formation of mRNA
• What is the template strand used for during transcription?

  It is called the antisense strand
• What occurs during translation?

  Amino acids join to form a polypeptide chain
• What is a gene?

  A series of bases coding for amino acids
• What is the genetic code?

  Order of bases coding for amino acids
• What do triplets of bases code for?

  A particular amino acid
• What happens to amino acids during protein synthesis?

  They are joined by peptide bonds to form chains
• What is the significance of non-coding sections of DNA?

  Not all genome codes for proteins
• What happens to tRNA molecules after they detach from amino acids?

  They detach from the amino acids.
• What leads to the formation of a polypeptide chain?

  The repeated process until a stop codon is reached.
• What is a gene?

  A series of bases on a DNA molecule.
• What does the genetic code consist of?

  Triplets of bases coding for amino acids.
• What do triplets of bases code for?

  A particular amino acid.
• How are amino acids joined together?

  By peptide bonds formed in condensation reactions.