AP Biology: Unit 2 - Cells

Cells

Cells

Building blocks of life, forming all living organisms

Prokaryotic cells

(e.g., bacteria) – Simple cells without a nucleus and membrane-bound organelles.

Eukaryotic cells

(e.g., plant and animal cells) – Complex cells with a nucleus and membrane-bound organelles.

Cell Membrane - Structure

Phospholipid bilayer with embedded proteins

Cell Membrane - Function

Controls the movement of substances in and out of the cell, providing protection and structural support

Cytoplasm - Structure

Gel-like substance inside the cell membrane, consisting of water, salts, and proteins

Cytoplasm - Function

Holds and supports cell organelles and facilitates metabolic reactions

Nucleolus - Structure

Dense region within the nucleus

Nucleolus - Function

Produces ribosomes, which are essential for protein synthesis

Mitochondria - Structure

Double membrane, with the inner membrane folded into cristae

Mitochondria - Function

Produces energy (ATP) through cellular respiration, often called the "powerhouse of the cell."

Ribosomes - Structure

Small structures made of RNA and proteins, found in the cytoplasm or attached to the endoplasmic reticulum (ER)

Ribosomes - Function

Synthesize proteins by translating messenger RNA (mRNA)

Endoplasmic Reticulum (ER)

Network of membranous tubules and sacs

Endoplasmic Reticulum (ER) - Rough ER

(has ribosomes attached): Involved in protein synthesis and transport; processes proteins

Endoplasmic Reticulum (ER) - Smooth ER

(no ribosomes): Involved in lipid synthesis and detoxification; synthesizes lipids and detoxifies chemicals

Golgi Apparatus - Structure

Stacks of flattened membranous sacs

Golgi Apparatus - Function

Modifies, sorts, and packages proteins and lipids for storage or transport out of the cell

Lysosomes - Structure (mostly animals)

Membrane-bound sacs filled with digestive enzymes

Lysosomes - Function (mostly animals)

Break down waste materials, cellular debris, and foreign invaders like bacteria

Centrioles - Structure

Small, cylindrical structures made of microtubules

Centrioles - Function

Help in organizing cell division by forming the spindle fibers that separate chromosomesC

Cytoskeleton - Structure

Network of protein filaments (microfilaments, intermediate filaments, and microtubules)

Cytoskeleton - Function

Provides structural support, maintains cell shape, and helps in cell movement and division

Cell Wall - Structure

Rigid outer layer made of cellulose

Cell Wall - Function (Plants Only)

Provides structural support and protection for plant cells

Chloroplasts - Structure (Plants Only)

Double membrane-bound organelles with internal structures (thylakoids) containing chlorophyll

Chloroplasts - Function (Plants Only)

Conduct photosynthesis, converting sunlight into chemical energy (glucose)

Vacuole - Structure

Large, membrane-bound sac filled with water and other materials

Vacuole - Function

Stores nutrients, waste products, and helps maintain turgor pressure (rigidity) in plant cells