AP Bio CH 4 studyguide

( the info from the black board )

Prokaryotic cell

small, single-celled organisms that lack a nucleus and membrane-bound organelles

Eukaryotic cell

larger, complex cells that contain a true nucleus and specialized membrane-bound structures

What is the structure of the Nucleus?

Enclosed by a double nuclear membrane with nuclear pores; contains chromatin (DNA) and the nucleolus

What is the function of the Nucleus?

Enclosed by a double nuclear membrane with nuclear pores; contains chromatin (DNA) and the nucleolus

What is the structure Mitochondria?

Double-membrane structure; the inner membrane folds into shelf-like structures called cristae.

What is the function of the Mitochondria?

Known as the powerhouse of the cell; produces ATP (energy) through cellular respiration

What is the structure of the Rough Endoplasmic Reticulum? ( Rough ER )

Folded membranous tubules studded with ribosomes on its outer surface

What is the function of the Rough Endoplasmic Reticulum? ( Rough ER )

Synthesizes and processes proteins meant for membrane insertion or secretion

What is the structure of the smooth Endoplasmic Reticulum? ( Smooth ER )

Folded membranous tubules lacking ribosomes.

What is the function of the smooth Endoplasmic Reticulum? ( Smooth ER )

Synthesizes lipids and phospholipids, metabolizes carbohydrates, and detoxifies poisons and drugs

What is the structure of the Golgi apparatus?

Series of flattened, membrane-bound sacs (cis and trans faces)

What is the function of the Golgi apparatus?

Modifies, sorts, and packages proteins and lipids from the ER for transport or export

What is the structure of the Lysosomes?

Small, single-membrane vesicles filled with acidic hydrolytic enzymes (pH ~5)

What is the function of the Lysosomes?

Acts as the waste disposal and recycling center by breaking down macromolecules, old organelles, and pathogens

What is the structure of the Peroxisomes?

Small, membrane-bound sacs containing oxidative enzymes

What is the function of the Peroxisomes?

Breaks down fatty acids and detoxifies harmful compounds, such as converting hydrogen peroxide into water and oxygen

What is the structure of the Vacuoles/ Central Vacuoles?

Large membrane-bound sacs (very large and central in plant cells; smaller in animal cells)

What is the function of the Vacuoles/ Central Vacuoles?

Stores water, nutrients, and waste products; maintains turgor pressure in plant cells

What is the structure of the Chloroplasts (only plant cells )?

Double-membrane organelle containing stacked thylakoid membranes (grana) and a green pigment called chlorophyll

What is the function of the Chloroplasts (only plant cells )?

Converts light energy into chemical energy through photosynthesis

What is the structure of the Ribosomes?

Small complexes made of rRNA and protein (found free in the cytoplasm or attached to the rough ER)

What is the function of the Ribosomes?

Translates RNA instructions into polypeptide chains (protein synthesis)

What is the structure of the Cytoskeleton?

Network of microfilaments, intermediate filaments, and microtubules

What is the function of the Cytoskeleton?

Provides mechanical support, maintains cell shape, and assists in intracellular transport and cell division

What is the structure of the Centrioles / Centrosomes? ( Only in animal cells )

Cylindrical structures made of microtubule triplets.

What is the function of the Centrioles / Centrosomes?( Only in animal cells )

Organizes the mitotic spindle fibers during cell division.

What is the structure of the Plasma ( Cell ) Membrane?

Selectively permeable phospholipid bilayer embedded with proteins and cholesterol (described by the fluid mosaic model)

What is the function of the Plasma ( Cell ) Membrane?

Regulates the movement of substances into and out of the cell and facilitates cell signaling.

What is the structure of the Cell wall? ( only in plant cells )

Rigid outer layer composed of cellulose (in plants) or chitin (in fungi)

What is the function of the Cell wall? ( only in plant cells )

Provides structural strength, protection, and prevents osmotic lysis

How does Endosymbiosis relate to the Mitochondria / Chloroplasts?

Endosymbiosis explains that Mitochondria and Chloroplasts originated as free-living prokaryotic bacteria that were engulfed by ancestral host cells

What is the pathway of a synthesized protein?

Rough ER -> Transport Vesicle -> Golgi Apparatus -> Destination

What is the cellular function that is primarily carried out by the Smooth Endoplasmic Reticulum (Smooth ER)

The Smooth ER lacks ribosomes and specializes in lipid and phospholipid synthesis, carbohydrate metabolism, and detoxification of poisons and drugs

Whats the function of tight junctions?

Form a watertight, leak-proof seal that blocks the movement of water, ions, and solutes between cells.

What is the function of Desosomes

Act as strong mechanical spot welds that bind intermediate filaments (like keratin) of adjacent cells, handling high tissue stress

What is the function of Gap junctions?

Form aqueous channels that allow direct passage of ions, small molecules, and electrical signals between cells

Whats the function of Plasmodesmata?

allow direct, regulated transport and communication

What are three main components of the Cytosketleton?

microfilaments, intermediate filaments, and microtubules

What is ECM?

a complex, non-cellular 3-dimensional network of macromolecules that surrounds and supports cells in tissues