Biology: Cell-level systems

• What does DNA stand for?

  Deoxyribonucleic acid
• What is the structure of DNA?

  Double helix
• How many strands does DNA have?

  2 strands
• What is the process of complementary base pairing in DNA?

  Specific pairing of nucleotides
• How many different nucleotides are there in DNA?

  4 different nucleotides
• What are the components of each nucleotide?

  Sugar, phosphate group, base
• What is the role of enzymes in metabolic reactions?

  Speed up the rate of reactions
• What are the four bases found in DNA?

  Adenine, Thymine, Cytosine, Guanine
• What base pairs with Adenine (A) in DNA?

  Thymine (T)
• What base pairs with Cytosine (C) in DNA?

  Guanine (G)
• What factors affect the rate of enzyme activity?

  Substrate concentration, pH, temperature
• What are the steps of protein synthesis?

  1. Transcription: DNA unzips, mRNA is formed
  2. Translation: mRNA travels to ribosome
  3. Amino acids are joined based on mRNA sequence
• What is the role of mRNA in protein synthesis?

  Acts as an amino acid courier
• What happens during transcription?

  DNA unzips and mRNA is copied
• What happens during translation?

  mRNA is translated into amino acids
• What is the chemical formula for glucose?

  C$6$H$12$O$6$
• What is the role of carbon dioxide in photosynthesis?

  It is a reactant in the process
• What is the equation for photosynthesis?

  6CO$2$ + 6H$2$O → C$6$H$12$O$6$ + 6O$2$
• What is the effect of light intensity on photosynthesis?

  Higher light intensity increases the rate
• What happens to light intensity as distance from the source increases?

  Light intensity decreases
• What is the formula for light intensity related to distance?

  Intensity ∝ 1/distance$^2$
• What are the main types of biological macromolecules and their building blocks?

  • Carbohydrates: made of monosugars
  • Proteins: made of amino acids
  • Lipids: made of fatty acids
  • Nucleic acids: made of nucleotides
• What is the function of the nucleus in a cell?

  Controls the cell and contains genetic material
• What is the role of mitochondria?

  Site of aerobic respiration
• What is the function of the cell membrane?

  Controls what moves in/out of the cell
• What is the role of ribosomes?

  Site of protein synthesis
• What is the function of cytoplasm?

  Where most chemical reactions take place
• What is the function of the cell wall in plant cells?

  Provides strength and support
• What is the role of chloroplasts?

  Site of photosynthesis
• What is the function of the permanent vacuole?

  Supports the cell and contains cell sap
• What are the differences between prokaryotic and eukaryotic cells?

  • Prokaryotic cells: no nucleus, circular DNA
  • Eukaryotic cells: have a nucleus, linear DNA
• What is the smallest distance between two points where they are seen as separate?

  Resolution
• What is the advantage of using an electron microscope?

  Greater detail and resolution
• What is a disadvantage of electron microscopy?

  Samples need to be placed in a vacuum
• What is the maximum magnification of a light microscope?

  x1500
• What is a disadvantage of light microscopy?

  Low resolution (100nm)
• What is the purpose of special training in microscopy?

  To operate advanced microscopes effectively
• What are the advantages and disadvantages of light and electron microscopy?

  Advantages of light microscopy:

  • Cheap
  • Can view live specimens

  
  

  Disadvantages of light microscopy:

  • Low resolution (100nm)

  
  

  Advantages of electron microscopy:

  • Greater detail and resolution

  
  

  Disadvantages of electron microscopy:

  • Samples need to be placed in a vacuum