Summary lec 2

Question 1

What are cells known as?

Answer 1

The basic unit of life.

Question 2

Why is understanding cell structure important?

Answer 2

It helps in studying diseases like cancer.

Question 3

What are the main components of cells?

Answer 3

Water, inorganic ions, and organic molecules (carbohydrates, lipids, proteins, nucleic acids).

Question 4

What are cell organelles?

Answer 4

Specialized structures within cells that perform distinct vital functions.

Question 5

What is the function of the cell membrane?

Answer 5

Separates the cell from the external environment and controls movement of substances in and out.

Question 6

What is another name for the cell membrane?

Answer 6

Plasma membrane.

Question 7

What type of permeability does the cell membrane have?

Answer 7

Semipermeable or selectively permeable.

Question 8

What is the cell membrane formed of?

Answer 8

A lipid bilayer.

Question 9

What are the components of the cell membrane?

Answer 9

Lipids (phospholipids, cholesterol), proteins (peripheral or integral), and carbohydrates.

Question 10

What theory describes the structure of the cell membrane?

Answer 10

The fluid mosaic theory.

Question 11

What does “fluid” mean in the fluid mosaic model?

Answer 11

The lipid bilayer is viscous, allowing phospholipids to move.

Question 12

What does “mosaic” mean in the fluid mosaic model?

Answer 12

The bilayer is embedded with various proteins like tiles in a mosaic.

Question 13

What is the cytoplasm made of?

Answer 13

Cytosol and organelles.

Question 14

What is cytosol?

Answer 14

The fluid portion of cytoplasm containing water, molecules, and ions.

Question 15

Where do many biochemical reactions occur?

Answer 15

In the cytoplasm.

Question 16

What forms the cytoskeleton?

Answer 16

Microtubules, microfilaments (actin filaments), and intermediate filaments.

Question 17

What is the function of the cytoskeleton?

Answer 17

Provides structural support, shape, and locomotion to the cell.

Question 18

What is the main function of the nucleus?

Answer 18

Controls cell activities.

Question 19

What encloses the nucleus?

Answer 19

The nuclear membrane (nuclear envelope).

Question 20

What is the function of nuclear pores?

Answer 20

Allow material exchange between the nucleus and cytoplasm.

Question 21

What does the nucleus contain?

Answer 21

Chromosomes (DNA) and a nucleolus.

Question 22

What is the nucleolus composed of?

Answer 22

RNA and protein.

Question 23

What is the function of the nucleolus?

Answer 23

Production of ribosomes.

Question 24

Which cells lack a nucleus?

Answer 24

Anucleate cells (e.g., red blood cells).

Question 25

What does anucleate mean?

Answer 25

Lacking a nucleus.

Question 26

What are polynucleated cells?

Answer 26

Cells with more than one nucleus.

Question 27

Give examples of polynucleated cells.

Answer 27

Skeletal muscle cells and liver cells.

Question 28

What are ribosomes made of?

Answer 28

RNA and proteins.

Question 29

How many subunits do ribosomes have?

Answer 29

Two subunits.

Question 30

What is the function of ribosomes?

Answer 30

Protein synthesis.

Question 31

What do free ribosomes produce?

Answer 31

Proteins used within the cell.

Question 32

What do ribosomes attached to RER produce?

Answer 32

Proteins for export outside the cell.

Question 33

What are the two types of endoplasmic reticulum?

Answer 33

Rough ER and Smooth ER.

Question 34

What is the function of the Rough ER?

Answer 34

Protein synthesis and transport.

Question 35

What gives the Rough ER its rough appearance?

Answer 35

Attached ribosomes.

Question 36

What are the functions of Smooth ER?

Answer 36

Lipid synthesis, detoxification, and calcium regulation.

Question 37

What is the function of the Golgi apparatus?

Answer 37

Processes, packages, and distributes proteins and lipids in vesicles.

Question 38

What is the function of mitochondria?

Answer 38

Produces ATP (energy) through respiration.

Question 39

What nickname is given to mitochondria?

Answer 39

Powerhouse of the cell.

Question 40

How many membranes does a mitochondrion have?

Answer 40

Two (double membrane).

Question 41

Does mitochondria have its own DNA?

Answer 41

Yes.

Question 42

What is the function of lysosomes?

Answer 42

Break down worn-out organelles, food particles, and foreign invaders.

Question 43

What do lysosomes contain?

Answer 43

Digestive enzymes.

Question 44

What is the function of peroxisomes?

Answer 44

Break down fatty acids and detoxify harmful substances like hydrogen peroxide.

Question 45

What enzymes do peroxisomes contain?

Answer 45

Oxidative enzymes.

Question 46

What are biomolecular condensates?

Answer 46

Membrane-less structures formed by phase separation of proteins, RNA, and biomolecules.

Question 47

How do biomolecular condensates differ from traditional organelles?

Answer 47

They lack a surrounding membrane.

Question 48

What process leads to the formation of biomolecular condensates?

Answer 48

Phase separation.

Question 49

What is phase separation?

Answer 49

A process where a homogeneous mixture divides into distinct regions with different properties.

Question 50

Give two examples of biomolecular condensates.

Answer 50

Nucleoli and stress granules.

Question 51

What is the function of nucleoli?

Answer 51

Ribosome synthesis.

Question 52

What is the function of stress granules?

Answer 52

Protect cells during stress by storing unused mRNA and proteins.

Question 53

Dysregulation of biomolecular condensates is linked to what disease?

Answer 53

Neurodegenerative diseases like Alzheimer’s.

Question 54

What are the main diagrams to study in this lecture?

Answer 54

Plasma membrane, mitochondria, ribosome, and eukaryotic cell structure.