Biology

• Enzymes are proteins that act like biological catalysts that speed chemical reactions
• Plant Cell components:

  • Cell wall
  • Mitochondrion
  • Chloroplast
  • Cell membrane
  • Cytoplasm
  • Vacuole
  • Nucleus
  • Ribosome
• Animal Cell components:

  • Mitochondrion
  • Cell membrane
  • Cytoplasm
  • Nucleus
  • Ribosome
• Fungal Cell components:

  • Cell wall
  • Mitochondrion
  • Cell membrane
  • Cytoplasm
  • Vacuole
  • Nucleus
  • Ribosome
• Bacterial Cell components:

  • Cell wall
  • Cell membrane
  • Ribosome
  • Plasmid
• Cell Wall:

  • Gives cell a rigid structure
• Mitochondrion:

  • Site of aerobic stages of respiration
• Cell Membrane:

  • Controls movement of substances in and out of the cell
• Chloroplasts:

  • Site of photosynthesis
• Cytoplasm:

  • Site of many chemical reactions
• Nucleus:

  • Controls cell activities, contains DNA
• Vacuole:

  • Stores cell sap, helps control water balance
• Ribosome:

  • Site of protein synthesis
• Plasmid:

  • Ring of DNA that can be removed in genetic engineering
• Cell Wall in Plant Cells:

  • Made of cellulose
• Cell Membrane consists of:

  • Proteins and phospholipids
• Cell Membrane is:

  • Selectively permeable
• Active Transport:

  • Requires energy for membrane proteins to move molecules and ions against the concentration gradient
• Passive Transport:

  • Involves substances moving down a concentration gradient and does not require energy
• Examples of Passive Transport:

  • Diffusion and osmosis
• Diffusion:

  • Movement of molecules down a concentration gradient
• Diffusion of Glucose and Oxygen:

  • Move into cell by diffusion. Concentration gradient running from outside of the cell to the inside
• Diffusion of Carbon Dioxide:

  • Move out of cell by diffusion. Concentration gradient running from inside the cell to the outside
• Osmosis:

  • Movement of water molecules from a higher to lower water concentration through a selectively permeable membrane
• Animal Cells can:

  • Burst when placed in solutions with a higher water concentration than their cell content
• Plants Cells can:

  • Become turgid if left in solutions with higher water concentration
• Animal Cells Shrink:

  • If placed in a solution with lower water concentration than their cell content
• Plant Cells Plasmolyse:

  • If placed in a solution with lower water concentration than their cell content
• Structure of DNA:

  • Double-stranded helix
• DNA Carries genetic information for making protein
• Four Bases:

  • Adenine, Cytosine, Guanine, Thymine
• Bases Pairing:

  • A-T, C-G
• Genetic Code:

  • The sequence of bases along a strand
• Base Sequence Determines:

  • Amino acid sequence in proteins
• Genes:

  • Section of DNA that codes for proteins
• Messenger RNA (mRNA):

  • Molecule that carries a complementary copy of the genetic code from DNA, in nucleus, to a ribosome, where protein is assembled from amino acids
• Variety of Protein Shapes and Functions:

  • Arises from sequence of amino acids
• Functions of Proteins:

  • Structural, enzymes, hormones, antibodies, receptors
• Enzymes:

  • Biological catalyst and are made by all living cells
• Function of Enzymes:

  • Speed up cellular reactions and are unchanged in the process