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 surface area and concentration difference increase 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 composes the cell membrane?

  A sea of phospholipids with proteins
• What is the main function of the cell membrane?

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

  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
• What increases the rate of gas exchange by diffusion?

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

  Transport of polar molecules via channel proteins
• 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?

  ATP hydrolysis
• What is endocytosis?

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

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

  Bases, sugar, and phosphate group

  
• What are the two types of nitrogenous bases?

  Purines and pyrimidines
• What are the purines in DNA?

  Adenine and guanine
• What are the pyrimidines in DNA?

  Cytosine and thymine
• What is the sugar in DNA?

  Deoxyribose
• What type of bonds hold the DNA structure together?

  Phosphodiester and hydrogen bonds
• What is the structure of DNA?

  Double-stranded alpha double helix
• What are the bases in mRNA?

  Adenine, guanine, cytosine, uracil
• What is the sugar in mRNA?

  Ribose
• What is the structure of tRNA?

  Single-stranded, folded into a specific pattern
• 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

  
• What is the role of RNA polymerase in transcription?

  Catalyzes the formation of mRNA
• What happens to mRNA after transcription?

  It moves out of the nucleus to ribosomes

  
• What occurs during translation?

  Amino acids join to form a polypeptide chain
• What is the genetic code?

  Order of bases coding for amino acids
• What is a gene?

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

  Each triplet codes for a specific amino acid
• What is the relationship between genes and polypeptide chains?

  Genes code for sequences of amino acids
• What sections of DNA do not code for proteins?

  Non-coding sections of the genome
• What happens to tRNA molecules after they detach from amino acids?

  They are released for reuse
• What leads to the formation of a polypeptide chain?

  The repeated attachment of amino acids