Cell Structure/Function

• Ribosomes

  Made of rRNA and protein. Proteins are assembled in base on mRNA codon sequence. Found in rough ER (leave cell) and free in cytosol (stay in cell). They are found in all cells
• Endoplasmic Reticulum


  Rough: provides space for proteins to be dropped off as they are synthesized.

  Smooth: detoxification and lipid synthesis
• Golgi Complex


  Correct folding and chemical modification of newly synthesized proteins and packaging of proteins. Cis= receiving, Trans=shipping
• Mitochondria

  Outer: smooth

  Inner: highly folded

  Provided compartments for metabolic reactions. Inner folds increase surface area, allowing more ATP to be made.

  Kreb cycle: matrix

  ETC and ATP synthesis in inner mitochondrial membrane
• Lysosomes


  Membrane-bound sacs. Store and release macromolecules, waste products, and large ones in plants to hold water for turgor pressure.
• Chloroplasts

  In plant cells, site of photosynthesis. Double membrane. They harness energy from sun and store it in chemical compounds. Thylakoid/grana= location of light dependent reactions of photosynthesis. Thylakoid membranes contain chlorophyll pigments and electron transport proteins.

  Stroma= fluid that fills chloroplasts, located inside double membrane and in between granum. Site of Calvin-Bensen Cycle/Carbon fixation reactions (when inorganic carbon from CO2 is added to organic molecules)
• Large animals slow metabolism, small animals fast metabolism


  Large=slow because they have lower surface area to volume, release heat slower. Small=fast because they have high surface area to volume, and lose heat fast
• Hydrophilic/hydrophobic tendencies of embedded proteins in cell membrane

  Can be hydrophilic with charge and polar side groups, or hydrophobic with nonpolar side groups
• What makes cell membrane selectively permeable?

  Structure of cell membrane. Hydrophilic head and hydrophobic tails, proteins, cholesterols, glycoproteins, and glycolipids on surface, or in membrane
• How do hydrophilic molecules like large polar molecules and ions move across membrane


  Embedded protein channels and transport proteins
• Why is compartmentalization important?

  To keep intracellular metabolic processes and specific enzymatic reactions separate
• How do membranes contribute to compartmentalization of cell functions like cellular respiration, photosynthesis, proteins synthesis

  To minimize competing interactions and increasing surface area where reactions can occur
• Endosymbiotic theory

  Mitochondria and chloroplasts thought to evolve from prokaryotic cells. Have own DNA, can replicate, have ribosomes, double membrane
• Is denaturing reversible?

  Yes, as long as their exposure to temp or pH isn't too extreme