UNIT 2: CELLS, MEMBRANES, + MOLECULAR TRANSPORT
A Tour of the Cell (Ch. 4)
- Describe the main differences between prokaryotes and eukaryotes
→ Prokaryotes: in bacteria, single celled organisms
→ Eukaryotes: in protists, animals, plants, fungi
- The functions and general locations of organelles
1. Nucleus - stores genetic information
2. Ribosomes - makes protein
3. Plasma membrane - separates the cell from the environment
4. Endoplasmic reticulum - makes proteins and lipids; Rough ER:
5. Golgi apparatus - sorts proteins
6. Lysosome - breaks down unwanted material
7. Mitochondria - makes energy for the cell
8. Chloroplast - makes food in plant cells
9. Vacuole - stores water in plant cells
10. Vesicles - ships materials around the cell
11. Cell wall - Rigid barrier that protects the cell
12. Cytoplasm - The interior contents of the cell
13. Cytosol - the gel like matrix of the cytoplasm
- How the “central dogma” (DNA to RNA to protein) takes place within the cell
organelles
→ DNA is replicated in the nucleus to create a copy DNA; DNA is transcribed into messenger
RNA in the nucleus, and messenger RNA is translated by ribosomes in the cytosol to create
a protein
- Differences between plant and animal cells
→ Plant cells: rigid cell wall, large vacuole, larger in size, have plastids, centrosomes
are absent, don’t have cilia, lysosomes are very rare
→ Animal cell: no cell wall, small vacuoles, smaller in size, don’t have plastids, have
centrosomes, have cilia, have lysosomes.
- Relationship between and importance of surface area:volume ratio in cells
→ More surface area of cell = less percentage of cube diffused
→ Less surface area of cell= more percentage of cube diffused
→ Same diffusing depth for all cells
- The reasoning behind the endosymbiont theory
→ Endosymbiosis theory: mitochondria and chloroplast in eukaryotic cells were once
prokaryotes that were ingested by a large prokaryote.
- The purpose of internal membranes
→ It regulates the passage of nutrients, metabolites, macromolecules, and information in
and out of the cytoplasm and maintains the proton motive force required for energy storage
Membrane Transport (Ch. 5.1-5.5)
The arrangement of phospholipids in a cell membrane
Hydrophilic head and hydrophobic tails; hydrophilic heads are next to each other and face
outwards, hydrophobic tails are in the inner part of the membrane
- How both plant and animal cells behave in hypertonic, hypotonic, and isotonic
solutions
A Tour of the Cell (Ch. 4)
- Describe the main differences between prokaryotes and eukaryotes
→ Prokaryotes: in bacteria, single celled organisms
→ Eukaryotes: in protists, animals, plants, fungi
- The functions and general locations of organelles
1. Nucleus - stores genetic information
2. Ribosomes - makes protein
3. Plasma membrane - separates the cell from the environment
4. Endoplasmic reticulum - makes proteins and lipids; Rough ER:
5. Golgi apparatus - sorts proteins
6. Lysosome - breaks down unwanted material
7. Mitochondria - makes energy for the cell
8. Chloroplast - makes food in plant cells
9. Vacuole - stores water in plant cells
10. Vesicles - ships materials around the cell
11. Cell wall - Rigid barrier that protects the cell
12. Cytoplasm - The interior contents of the cell
13. Cytosol - the gel like matrix of the cytoplasm
- How the “central dogma” (DNA to RNA to protein) takes place within the cell
organelles
→ DNA is replicated in the nucleus to create a copy DNA; DNA is transcribed into messenger
RNA in the nucleus, and messenger RNA is translated by ribosomes in the cytosol to create
a protein
- Differences between plant and animal cells
→ Plant cells: rigid cell wall, large vacuole, larger in size, have plastids, centrosomes
are absent, don’t have cilia, lysosomes are very rare
→ Animal cell: no cell wall, small vacuoles, smaller in size, don’t have plastids, have
centrosomes, have cilia, have lysosomes.
- Relationship between and importance of surface area:volume ratio in cells
→ More surface area of cell = less percentage of cube diffused
→ Less surface area of cell= more percentage of cube diffused
→ Same diffusing depth for all cells
- The reasoning behind the endosymbiont theory
→ Endosymbiosis theory: mitochondria and chloroplast in eukaryotic cells were once
prokaryotes that were ingested by a large prokaryote.
- The purpose of internal membranes
→ It regulates the passage of nutrients, metabolites, macromolecules, and information in
and out of the cytoplasm and maintains the proton motive force required for energy storage
Membrane Transport (Ch. 5.1-5.5)
The arrangement of phospholipids in a cell membrane
Hydrophilic head and hydrophobic tails; hydrophilic heads are next to each other and face
outwards, hydrophobic tails are in the inner part of the membrane
- How both plant and animal cells behave in hypertonic, hypotonic, and isotonic
solutions
