Ch3 Bio LEC: Cell Structure & Function: Prokaryotes, Eukaryotes, Organelles, Membranes, Transport, and Respiration

What are the three main statements of cell theory?

1. All living things are composed of cells. 2. A single cell is the smallest unit that exhibits all the characteristics of life. 3. All cells come only from preexisting cells.

What is the key distinction between prokaryotic and eukaryotic cells?

Eukaryotic cells have a nucleus and membrane-bound organelles, while prokaryotic cells do not.

What type of cells are bacteria and archaea?

Prokaryotic cells.

What is the function of the plasma membrane?

To separate the cell from its environment, control what enters and leaves, and allow information transfer.

What does the nucleus contain?

DNA and chromosomes; it controls cellular activities.

What is the difference between cytoplasm and cytosol?

Cytoplasm includes all internal contents of the cell excluding the nucleus, while cytosol is the gel-like fluid within the cytoplasm.

What is the primary job of ribosomes?

Protein synthesis.

What distinguishes rough ER from smooth ER?

Rough ER has ribosomes attached and is involved in protein manufacturing, while smooth ER has no ribosomes and is involved in lipid synthesis.

What is the function of the Golgi apparatus?

To refine, package, and ship cellular products.

What are vesicles and their primary functions?

Storage and transportation containers within the cell.

What is the role of mitochondria in the cell?

To generate ATP and energy through cellular respiration.

What is the function of lysosomes?

To digest waste and cellular debris.

What do peroxisomes do?

Detoxify wastes.

What is the cytoskeleton's role in the cell?

To provide internal support and maintain cell shape.

What is the structure of the plasma membrane?

A phospholipid bilayer with polar heads facing outward and nonpolar tails facing inward.

What are the three major types of transport across the cell membrane?

Passive transport, active transport, and bulk transport.

What is diffusion?

The movement of molecules from high concentration to low concentration without energy.

What is osmosis?

The diffusion of water across a selectively permeable membrane.

What is facilitated diffusion?

A passive transport process that requires no ATP, allowing molecules to cross membranes with the help of proteins.

What is the difference between endocytosis and exocytosis?

Endocytosis is the process of bringing substances into the cell, while exocytosis is the process of exporting substances out of the cell.

What is the main function of cilia?

To move substances along the surface of cells; they are short and numerous.

What is the main function of flagella?

To enable movement; they are long and usually single.

What is the significance of cholesterol in the plasma membrane?

Cholesterol increases the mechanical strength of the membrane.

What is the role of proteins in the plasma membrane?

To help transport molecules and transmit information.

What is the memory trick for remembering prokaryotes and eukaryotes?

Eukaryotes = elaborate (nucleus + organelles); Prokaryotes = primitive/simple (no nucleus + no organelles).

What are the two types of ribosomes and their functions?

Free ribosomes make proteins for immediate use; bound ribosomes make proteins for export or transport.

What is the function of the cytoskeleton's microtubules and microfilaments?

They provide structural support and help anchor cellular structures.

What are examples of substances that undergo facilitated diffusion?

Glucose and amino acids.

What is active transport?

A process that moves substances against their concentration gradient (from low to high concentration) and requires ATP or another energy source.

What does the sodium-potassium pump do?

It pumps 3 Na⁺ ions out of the cell and brings 2 K⁺ ions into the cell, using ATP.

What is endocytosis?

The process by which a cell membrane surrounds a substance and brings it into the cell in a vesicle.

What is exocytosis?

The process by which a vesicle fuses with the plasma membrane and releases its contents outside the cell.

What does tonicity refer to?

The relative concentration of solutes in two fluids.

What happens to a cell in an isotonic solution?

The solute concentration outside the cell is equal to that inside, resulting in no net movement of water and the cell remains normal size.

What is the result of placing a cell in a hypertonic solution?

The outside solution has a higher solute concentration, causing water to move out of the cell and the cell to shrink.

What occurs when a cell is placed in a hypotonic solution?

The outside solution has a lower solute concentration, causing water to move into the cell, which may swell and burst.

What is metabolism?

The sum of all chemical reactions in an organism.

What is anabolism?

The process of building larger molecules from smaller ones, which requires energy.

What is catabolism?

The process of breaking down larger molecules into smaller ones, which releases energy.

What are the four stages of cellular respiration?

1. Glycolysis 2. Preparatory step 3. Citric acid cycle 4. Electron transport chain + oxidative phosphorylation.

Where does glycolysis occur?

In the cytoplasm.

What happens during the preparatory step of cellular respiration?

Pyruvates are converted into Acetyl CoA, producing CO₂ and NADH.

What is produced during the citric acid cycle?

NADH, FADH₂, 2 ATP per glucose, and CO₂.

Where does the electron transport chain occur?

In the inner mitochondrial membrane.

What is the final electron acceptor in the electron transport chain?

Oxygen.

What is the function of ATP synthase?

It uses the flow of H⁺ ions to drive ATP production.

What is the cell theory?

1. All living things are made of cells. 2. The cell is the smallest unit showing characteristics of life. 3. Cells come from preexisting cells.

What distinguishes prokaryotic cells from eukaryotic cells?

Prokaryotes lack a nucleus and membrane-bound organelles, while eukaryotes have both.

What is the function of ribosomes?

They are responsible for protein synthesis.

What is the role of the Golgi apparatus?

To refine, package, and ship proteins.

What is the structure of the cell membrane?

A phospholipid bilayer with polar heads facing water and nonpolar tails facing inward.

What is the golden rule of water movement in relation to solute concentration?

Water moves toward the higher solute concentration.

What is the difference between diffusion and osmosis?

Diffusion is the movement of solutes from high to low concentration, while osmosis specifically refers to the movement of water from low solute concentration to high solute concentration.