DO NOW- write in complete sentences
• 1. What is the evidence that led to
the Cell theory?
2. What are the 3 statements of the
3. What is surface to volume ratio?
• 4. Why are smaller cells better than
• 5. What are the basic parts of a cell?
2 Basic Types of Cell Types
• PROKARYOTE • EUKARYOTE
– No nucleus – Nucleus present
– No membrane- bound – Membrane-bound
– DNA is floating in the – Larger than prokaryotes
cytoplasm – Ex. WBC, sperm, skin
– Ex.Bacteria cell, most cells
Features and the Functions
• 1. CELL WALL: protects and maintains shape
of the cell.
– Composed of carb-protein complex called
– Some bacteria have extra layer of polysaccharide
that helps it stick to things. Ex. Bacteria sticking to
teeth, skin and food.
2. The CELL MEMBRANE is just inside the cell
– It controls the movement of materials in and out
• Prokaryotic cells reproduce by binary fission
and the cell membrane plays a role in this.
• There are no compartments in bacterial cells
so all cellular processes take place in the
• 3. PILI : Hair-like structures that are used for
attachment. Main function is to join bacterial
cells together for the transfer DNA from one
cell to another.
• 4. FLAGELLA: longer than pili. Used for cell
• 5. RIBOSOMES: in all prokaryotic cells.
Function to site of protein synthesis.
– Gives electron microscope pictures a granular
• 6. NUCLEOID REGION: area within the
bacterial cell that contains the circular threads
Cell Organelles and Functions
• 1. Plasma Membrane: also called the Cell
– Allows only certain molecules to enter or
leave the cell.
– It separates internal reactions from outside
– Also allows cell to excrete waste from the
• Made of PHOSPHOLIPIDS. Phospholipids
have a polar end and a nonpolar end.
• Most functions of the cell are controlled by
• Functions: “Brain” of the cell.
• It houses and protects the cell’s genetic
• When the cell is not dividing, the DNA exists in
long strands. While the cell is dividing, it coils
up to form CHROMOSOMES.
• The nucleus is the site where DNA is
transcribed into RNA.
• Nucleolus: dense part of the nucleus.
• Site where DNA is concentrated.
• Nuclear Envelope: double layer that covers
the nucleus. Also made of 2 phospholipid
• Nuclear Pores: holes in the nuclear envelope
that allow passageways for RNA and other
things entering and leaving the nucleus.
• 3. CYTOPLASM: area within the plasma
membrane excluding the nucleus.
• 4. MITOCHONDRION: tiny, double-membrane
organelles that transfer ENERGY from organic
molecules to ATP.
• ATP powers most of the cell’s chemical
• Function: Powerhouse of the cell.
• Active cells have many mitochondrion. Ex.
• Inner folds: CRISTAE. Cristae contain proteins
that carry out energy-harvesting chemical
• 5. RIBOSOMES: small, spherical organelles.
• Function: make proteins.
• Don’t have a membrane.
• Assembly begins in the nucleolus and is
completed in the cytoplasm.
• Consists of a large and small subunit.