BIO Exam #2

• Where is the DNA located in a prokaryotic cell?

  Nucleoid
• What structures do ALL cells have?

  plasma(cell) membrane, DNA, ribosomes, cytoplasm (or cytosol)
• What structure really defines the boundaries of the cell, and controls the passage of substances in and out of the cell?

  Plasma membrane
• What are some structures of prokaryotic cells?

  flagella, pili, or fimbriae, peptidoglycan layer, capsule
• Light microscopy


  highest magnification 100x & specimens can be alive, if unstained
• Electron microscopy

  magnification up to 100,000x & specimens must be dead
• Lysosome

  contains digestive enzymes for breaking down macromolecules
• Nucleolus


  dense area inside the nucleus where ribosomes are assembled
• Vacuole


  large storage compartment commonly found in plants and fungi
• Nucleus

  contains the generic material (DNA) of the cell
• Ribosome

  site of protein synthesis
• Smooth endoplasmic reticulum

  tubular structure for modification of toxins and lipid synthesis
• Golgi apparatus

  stack of flattened sacs which sort and package proteins
• Nuclear envelope

  double membrane surrounding the nucleus
• Rough endoplasmic reticulum


  membrane structure where ribosomes "dock" while making proteins
• Lysosome

  contains digestive enzymes for breaking down macromolecules
• Plasma membrane

  membrane surrounding the cell
• Microfilaments are assembled from what protein monomer?

  actin
• What structure have plant cells developed to allow for easier communication and passage of molecules from cell to cell?

  plasmodesmata
• What is primarily responsible for maintaining a cell's proper shape?

  a cytoskeleton framework
• Intermediate filaments


  tough, ropelike fibers that anchor organelles in place
• Microtubules


  responsible for swimming movement via cilia and flagella
• Microfilaments


  responsible for muscle contraction, cell crawling movement
• What fiber type can easily assemble and disassemble to change the length of the fiber?

  microtubules
• The strong fibrous component of plant cell walls is typically

  cellulose
• If the outside of a cell is hypertonic compared to the inside of the cell, which way will water diffuse across the cell membrane?

  Out of the cell
• Channel proteins are a form of facilitated diffusion which primarily allow what to flow across the membrane?

  ions and water
• the bath sol has less total solute than the inside of the cell so the bath is

  hypotonic
• the bath sol has more total solute than the inside of the cell, so the bath is

  hypertonic
• What is not found in membranes?

  nucleic acids
• A bilayer of phospholipid molecules makes and effective selectively permeable barrier between 2 water-filled spaces because of

  the hydrophobic core of the bilayer
• carrier proteins are a form of facilitated diffusion that transport molecules across a membrane especially large polar molecules like


  sugars and amino acids
• What kind of energy is required for a molecule to diffuse from a high concentration to a lower concentration?

  no energy is required - this is a passive process
• What is an electrochemical gradient?


  the combined forces of concentration and electrical charge which affect ion diffusion
• form of endocytosis that surrounds a large particle is called


  phagocytosis
• Secondary active transport molecules are able to transport larger molecules like sugars AGAINST their concentration gradient using energy from 


  allowing an ion (often Na+) to flow down its concentration gradient
• What sorts of substances are brought into cells by pinocytosis?

  fluid (water and dissolved substances)
• In each complete cycle of the Na+/K+ ATPase how many ions are moved?

  3 Na+ ions are moved out of the cell while 2 K+ ions are moved into the cell
• the process of photosynthesis involves the building up of sugar and is


  anabolic
• The ATP molecule is an


  adenosine nucleoside with 3 phosphate groups attached to it