Lecture 1 (SP2024)- What is a cell?

Question 1

Explain the “cell theory”

Answer 1

1. Cell = structural unit o/ life
2. Cells can only come from other cells
3. All orgs. are made up o/ 1+ cells
   - Bacteria are single cells
   - Humans are made up o/ many diff. cells

Question 2

T/F: Viruses are NOT cells

Answer 2

True

Question 3

Functions a cell needs to perform

Answer 3

1. Obtain food/energy- Find it, taking it in, convert it to something usable
2. Adjust and adapt to the environment- Keep bad tings out and good things in; getting enough oxygen, respond to changes in pH, preventing from drying out
3. Reproduce- Requires a lot of energy, how to get the right content into a daughter cell
4. Fulfill specialized functions: Neurons send/receive signal “knowing” what to do
5. Communication- Within the cells and w/ other cells, coordination between cells
6. Maintenance/repair: of various parts o/ the cell; taking out “trash”

Question 4

Prokaryotic vs eukaryotic (generalization)

Answer 4

Share
All cells are COMPLEX and WELL-ORDERED
Molecular structure o/ plasma membranes, DNA
Molecular mechanisms for transcription, translation, metabolic and energy pathways, breaking down proteins
Differ by
Membrane-bound organelles (e.g. a nucleus)
Size
Complex intracellular communication and transport of molecules
Copy # of genes per cell, DNA organization

Question 5

What are the characteristics of prokaryotes?

Answer 5

Bacteria and archaea
- One-celled org.
- Smaller
- No nucleus or organelles
- Have: circular DNA (nucleoid), plasma membrane, ribosomes, cytoplasm, & cell wall
- Can be diff. shapes
- Reproduction by fission

Question 6

What are the characteristics of eukaryotes?

Answer 6

Protists, fungi, plants, and animals
- Can be made up of many cells
- Bigger
- Membrane-bound nucleus w/ pores and linear chromosomes
- Plasma membrane (plus cell wall in plants)
- Many organelles
- Complex cytoskeleton
- Some sexual reproduction
- Plants carry out photosynthesis

Question 7

Mitochondria

Answer 7

• Powerhouse
• Site o/ ATP generation
• really important membrane system
• Has its own genome

Question 8

Endomembrane system

Answer 8

• Nuclear envelope
• ER (rough and smooth), vesicles
• Interconnected, close, membrane-bound system for trafficking
• Biosynthesis: Proteins (rough), phospholipids and fatty acids (smooth)

Question 9

Lysosome

Answer 9

• Digestive organelle
• Endocytic pathway

Question 10

Golgi

Answer 10

• Protein processing
• Modification
• Sorting

Question 11

Peroxisome

Answer 11

• Oxidative reactions
• Lipid biosynthesis

Question 12

Nucleus

Answer 12

• DNA/chromatin
• Ribosome assembly