lecture 1 - what is a cell?

Question 1

how many cells in the human body?

Answer 1

37.2 trillion

Question 2

describe cell theory

Answer 2

1. All living organisms are composed of one or more cells
2. The cell is the most basic unit of life
3. All cells arise from pre-existing cells

Question 3

common to all cells (6)

Answer 3

plasma membrane, DNA, ribosomes, cytoplasm, transcription, translation

Question 4

prokaryotic cells

Answer 4

• small, 1-2 μm
• DNA contained in nucleoid region
• no nucleus
• no membrane bound organelles

Question 5

eukaryotic cells

Answer 5

• large, 10–100 μm
• nuclear membrane surrounds DNA
• has nucleus
• has membrane bound organelles

Question 6

6 functions of a cell

Answer 6

1. obtain energy
2. adjust/adapt to environment
3. reproduce
4. fulfill specialized functions
5. communication
6. maintenance/repair

Question 7

viruses

Answer 7

• are not cells
• require cells to replicate
• can infect cells and cause cell death

Question 8

cell membrane

Answer 8

• separates inside of cell from outside
• phospholipid bilayer
• composed of lipids, proteins, and carbohydrates
• selectively allows molecules in/out

Question 9

nucleus

Answer 9

contains DNA

Question 10

nucleolus

Answer 10

site of ribosomal RNA synthesis and assembly of ribosome components

Question 11

nucleoplasm

Answer 11

non-nucleolar regions of nucleus

Question 12

nuclear matrix

Answer 12

composed of intermediate filaments called lamin, provides strucutral support

Question 13

nuclear pore complex

Answer 13

materials move into and out of the nucleus

Question 14

nuclear outer membrane…

Answer 14

is connected to the rough endoplasmic reticulum

Question 15

endomembrane system

Answer 15

includes nuclear envelope, endoplasmic reticulum, golgi apparatus, lysosome, vacuoles, vesicles, endosomes, plasma membrane
- function: modify, package, and transport lipids and proteins throughout cell

Question 16

endoplasmic reticulum

Answer 16

intracellular transporting system

Question 17

golgi complex

Answer 17

modifying, sorting, and packaging proteins and lipids into vesicles for delivery to targeted destinations

Question 18

lysosomes

Answer 18

• contains enzymes called acid hydrolases that degrade polymers into their monomeric subunits
• acidic pH of ~5

Question 19

mitochondria

Answer 19

• site of aerobic respiration and ATP production
• enzymes in matrix and cristae convert glucose to CO2 and H2O and release ATP

Question 20

cytosol

Answer 20

• contains cellular proteins, fats, carbohydrates
• interactions between macromolecules occur in cytosol
• contains cytoskeletal proteins important for structure

Question 21

cytoskeleton

Answer 21

• microtubules, microfilaments, intermediate filaments
• provides strength, rigidity, and mobility