2 Inside The Cell

Question 1

What are the two main types of cells?

Answer 1

Prokaryotic Cells and Eukaryotic Cells

Prokaryotic cells include domains Bacteria and Archaea, while Eukaryotic cells include Domain Eukarya (plants, animals, fungi, protists).

Question 2

What are the four components all cells have?

Answer 2

• Plasma membrane
• Cytosol
• Chromosomes
• Ribosomes

Question 3

What characterizes prokaryotic cells?

Answer 3

No nucleus and a single circular DNA molecule in the nucleoid region

Question 4

What are plasmids?

Answer 4

Small DNA molecules that contain ‘extra’ genes

Question 5

What are some simple organelles found in prokaryotic cells?

Answer 5

• Store calcium ions
• Hold magnetite crystals
• Organize enzymes that build organic compounds

Question 6

What is the function of photosynthetic membranes in prokaryotes like cyanobacteria?

Answer 6

Convert kinetic energy from sunlight into chemical energy

Question 7

What is peptidoglycan?

Answer 7

A structural component of bacterial cell walls

Question 8

What distinguishes eukaryotic cells from prokaryotic cells?

Answer 8

DNA in a nucleus bounded by a membranous nuclear envelope

Question 9

What is the endomembrane system?

Answer 9

A system of functionally interconnected organelles

Question 10

Name three components of the endomembrane system.

Answer 10

• Nuclear envelope
• Endoplasmic reticulum
• Golgi apparatus

Question 11

What is the function of the rough endoplasmic reticulum (RER)?

Answer 11

Site of protein synthesis with ribosomes attached

Question 12

What is the primary function of the smooth endoplasmic reticulum (SER)?

Answer 12

Lipid synthesis and detoxification

Question 13

What is exocytosis?

Answer 13

Vesicle buds off the endomembrane system and fuses with the plasma membrane to deliver contents outside the cell

Question 14

What do lysosomes contain?

Answer 14

Enzymes to catalyse hydrolysis of damaged or unneeded macromolecules

Question 15

What is endosymbiosis?

Answer 15

The theory that mitochondria and chloroplasts originated from engulfed bacteria

Question 16

What are the main functions of mitochondria?

Answer 16

Sites of cellular respiration and ATP generation

Question 17

What do chloroplasts do?

Answer 17

Capture sunlight energy to synthesize simple sugars

Question 18

What are microtubules composed of?

Answer 18

Tubulin proteins

Question 19

What is the function of microfilaments?

Answer 19

Maintain cell shape, enable movement, and transport organelles

Question 20

What are cilia and flagella used for?

Answer 20

Locomotion in some eukaryotic cells

Question 21

What type of movement do dynein proteins facilitate in cilia and flagella?

Answer 21

Bending movement by ‘walking’ along microtubules

Question 22

What are intermediate filaments made of?

Answer 22

Polymers of intermediate filament proteins

Question 23

What role do lamins play in the cell?

Answer 23

Support the nuclear envelope

Question 24

Fill in the blank: The nucleus contains _______.

Answer 24

DNA packed into multiple chromosomes

Question 25

True or False: All eukaryotic cells have the same organelles.

Answer 25

False

Question 26

What is the lumen in the endoplasmic reticulum?

Answer 26

The interior space of the ER

Question 27

What is the function of the Golgi apparatus?

Answer 27

Further modifies, sorts, and synthesizes proteins and lipids

Question 28

What are intermediate filaments primarily composed of?

Answer 28

Polymers of intermediate filament proteins ## Footnote They combine to form strong, cable-like structures that convey mechanical strength to cells.

Question 29

What type of protein subunits are intermediate filaments made of in epithelial cells?

Answer 29

Keratin ## Footnote Keratin is a key protein that forms intermediate filaments in epithelial cells.

Question 30

What are lamins and where are they found?

Answer 30

A type of intermediate filament found inside the nucleus ## Footnote They support the nuclear envelope.

Question 31

Name three organelles present in plant cells but not in animal cells.

Answer 31

Chloroplasts, cell wall, central vacuole ## Footnote These organelles are unique to plant cells.

Question 32

What is the role of the nucleus in a cell?

Answer 32

Contains genetic material and controls cellular activities ## Footnote It is essential for cell regulation and function.

Question 33

What is the function of the endomembrane system?

Answer 33

To work together in the secretory pathway ## Footnote It includes various organelles that coordinate to transport proteins.

Question 34

How does a ribosome become bound to the rough endoplasmic reticulum?

Answer 34

By recognizing a signal peptide on the nascent protein ## Footnote This process allows the ribosome to synthesize proteins into the lumen.

Question 35

List at least three general destinations for proteins made in the endomembrane system.

Answer 35

* Plasma membrane * Lysosomes * Secretory vesicles ## Footnote These destinations are crucial for protein function and distribution.

Question 36

What are three pathways for macromolecular recycling via lysosomes?

Answer 36

Autophagy, phagocytosis, endocytosis ## Footnote These pathways allow the cell to recycle and degrade macromolecules.

Question 37

Compare and contrast mitochondria and chloroplasts.

Answer 37

Mitochondria are involved in cellular respiration, chloroplasts in photosynthesis ## Footnote Both organelles have double membranes and are involved in energy conversion.

Question 38

What is the evidence for endosymbiosis?

Answer 38

Presence of double membranes, own DNA, and ribosomes in mitochondria and chloroplasts ## Footnote This supports the theory that these organelles originated from free-living prokaryotes.

Question 39

What are the three types of cytoskeletal elements?

Answer 39

* Microtubules * Microfilaments * Intermediate filaments ## Footnote Each type has distinct structures and functions within the cell.

Question 40

Describe the general structure of cilia and flagella.

Answer 40

Composed of microtubules arranged in a '9+2' arrangement ## Footnote This structure is essential for their movement and function.

Question 41

How is bending in cilia and flagella generated?

Answer 41

By the action of dynein motor proteins ## Footnote Dynein facilitates movement along microtubules.

Question 42

Compare the functions of kinesin, dynein, and myosin motor proteins.

Answer 42

* Kinesin: Anterograde transport * Dynein: Retrograde transport * Myosin: Muscle contraction and motility ## Footnote Each motor protein has a specific role in cellular transport and movement.

Question 43

List at least five ways in which microfilaments and myosin proteins interact to generate cellular motility.

Answer 43

* Muscle contraction * Cell division * Amoeboid movement * Cytokinesis * Cell shape changes ## Footnote These interactions are fundamental for various forms of cellular movement.