post lecture quiz

Question 1

main components of cell theory

Answer 1

• all organisms are composed of one or more cells
• the cell is the basic unit of structure and organization in organisms
• all cells come from pre-existing cells

Question 2

difference between prokaryotic and eukaryotic cells

Answer 2

• prokaryotic cells have no nucleus nor other membrane bound organelles
• no internal membrane system
• has nucleoid region
• eukaryotic cells have membrane bound organelles (nucleus, endomembrane system)
• a cytoskeleton

Question 3

similarities between prokaryotic and eukaryotic cells

Answer 3

• plasma membrane
• cytoplasm
• dna
• ribosomes

Question 4

what is endocytosis

Answer 4

• capture a particle from outside into a cell by forming a vesicle
  
  • phagocytosis: capturing of large material
  • pinocytosis: capturing of liquid
• receptor-mediated endocytosis: the transfer of specific molecules into the cell through binding to receptors

Question 5

what is exocytosis

Answer 5

• release stuff from the cell through the formation of vesicle

Question 6

what is diffusion

Answer 6

• the tendency of molecules to move from an area of high concentration to an area of low concentration
• selective permeability: only a certain molecule can pass through a membrane
• concentration gradient: the concentration difference of a substance over a distance

Question 7

what does diffusion depend on?

Answer 7

• steepness of the gradient
• surface area
• mass
• solvent density
• solubility
• physical factors: temperature, pressure, electrical field, distance

Question 8

what is facilitated diffusion

Answer 8

• materials pass through the cell with the help of proteins
• protein channels: open channels polar molecules
• carrier proteins: sugars, amino acids, and ions

Question 9

what is osmosis

Answer 9

• the diffusion of water through a semipermeable membrane
  
  • the movement of water from high to low concentration
  • a solute: the stuff that dissolves into a solution

Question 10

differences between diffusions

Answer 10

• standard diffusion is molecules migrating from areas of high to low concentration
• facilitated diffusion is when materials move past cells with help of protein
• osmosis is the diffusion for water molecules through semipermeable membrane

Question 11

what is active transport

Answer 11

• requires energy to move molecules against the concentration gradient
• ATP: the currency of a cell

example: sodium-potassium pump which transmits signals along a nerve cell

Question 12

difference between diffusion and active transport

Answer 12

• diffusion, osmosis, and facilitated diffusion is all passive transport which does not require energy.
• active transport requires energy to move molecules across the cell membrane

Question 13

difference between animal and plant cells

Answer 13

• animal cells have centrioles, which are vital for cell division.
• plant cells have large central vacuole (storage center), tonoplast (mediates solutes & water), chloroplast (photosynthesis), and cell walls (support and protection)