Ions, Anions and Cations

1.1 – Plant and Animal Cells

Prokaryotes vs Eukaryotes:

Prokaryotes: No nucleus, simple structure, no membrane-bound organelles (e.g., bacteria).

Eukaryotes: Have a nucleus and membrane-bound organelles (e.g., plant and animal cells).

Organelles – Structures and Functions:

            Animal & Plant Cells:

•	Cell Membrane: Controls what enters and leaves the cell; provides protection.

•	Cytoplasm: Jelly-like substance where cell organelles are suspended.

•	Cytoskeleton: Provides structure and shape; aids in movement within the cell.

•	Nucleus: Contains DNA; controls cell functions.

•	Chromatin: Uncondensed DNA; found during interphase.

•	Chromatids: Each of the two identical halves of a replicated chromosome.

•	Chromosomes: Condensed DNA visible during mitosis; carries genetic info.

•	Ribosomes: Site of protein synthesis.

•	Endoplasmic Reticulum (ER):

•	Rough ER – has ribosomes; protein synthesis.

•	Smooth ER – no ribosomes; lipid synthesis.

•	Golgi Apparatus: Modifies, sorts, and packages proteins/lipids for transport.

•	Centrioles: Help in cell division (spindle formation).

•	Mitochondria: “Powerhouse”; site of cellular respiration, produces ATP.

            Animal Only:

•	Lysosomes: Contain enzymes to break down waste and cellular debris.

            Plant Only:

•	Chloroplasts: Site of photosynthesis; contains chlorophyll.

  • Vacuoles: Large central vacuole stores water and maintains turgor pressure.

•	Cell Wall: Provides structure and protection; made of cellulose.

1.2 – The Cell Cycle & Mitosis

Phases of the Cell Cycle:

**Interphase**: Cell grows and prepares for division.

•	G1: Cell grows and performs normal functions.

•	S (Synthesis): DNA is replicated because the cell has grown to a point where it can't function properly..

•	G2: Prepares for mitosis.

•	G0: Resting phase; cell is not dividing.

**Mitosis**:

•	Prophase: Chromatin condenses into chromosomes; nuclear envelope dissolves. chromosomes grow

•	Metaphase: Chromosomes align at the metaphase plate. make a line in the middle

•	Anaphase: Sister chromatids are pulled apart to opposite poles. pull apart to each side

•	Telophase: Nuclear envelope re-forms; chromosomes de-condense. split to two circles 

**Cytokinesis**:

•	Animal Cells: Cell membrane pinches in and then pulls apart (cleavage furrow).

•	Plant Cells: Cell plate forms to divide the cytoplasm.

            Necrosis vs Apoptosis:

•	Necrosis: Unplanned cell death due to injury or damage.

•	Apoptosis: Programmed cell death; natural and controlled.

            Asexual vs Sexual Reproduction:

•	Asexual: One parent; offspring are genetically identical (e.g., mitosis).

•	Sexual: Two parents; offspring are genetically diverse.

1.3 – Specialized Cells

            Regeneration:

•	The ability to regrow damaged or missing body parts (e.g., starfish, lizards).

            Stem Cells:

•	Undifferentiated cells that can become various types of specialized cells.

            Animal Tissues – Function and Examples:

• Epithelial Tissue: Covers body surfaces and lines organs ( Ex: Skin, lining of       digestive tract. )

•	Connective Tissue: Supports, binds, and protects organs ( Ex : Blood, bone, cartilage, fat. )

            3 Components of Blood:

•	Red blood cells (carry oxygen),

•	White blood cells (fight infection),

•	Platelets (clotting).

**Muscle Tissue:**

•	Enables movement.

•	3 Types: Skeletal (voluntary), Cardiac (heart), Smooth (organs).

**Nervous Tissue:**

•	Sends and processes electrical signals.

•	Made of neurons and supporting cells.

            Plant Tissues – Function:

**Epidermal Tissue**:

•	Outer protective layer.

•	Stomate (Stomata): Pores for gas exchange.

**Ground Tissue:**

•	Performs photosynthesis and stores nutrients.

**Photosynthesis**:

•	Reactants: CO₂ + H₂O + sunlight

•	Products: Glucose (C₆H₁₂O₆) + O₂

**Vascular Tissue**:

•	Transports substances.

•	Xylem: Carries water and minerals from roots to leaves.

•	Phloem: Carries sugars from leaves to the rest of the plant.

**Meristematic Tissue:**

•	Responsible for plant growth; contains actively dividing cells.