1. Eukaryotic Cells Eukaryotic cells are characterized by having
DNA in a nucleus that is bounded by a membranous nuclear envelope
Membrane-bound organelles
Cytoplasm in the region between the plasma membrane and nucleus
Eukaryotic cells are generally much larger than prokaryotic cells

2. Plasma Membrane
The plasma membrane is a selective barrier that allows sufficient passage of oxygen, nutrients, and waste to service the volume of every cell
The general structure of a biological membrane is a double layer of phospholipids

4. Surface Area to Volume
The logistics of carrying out cellular metabolism sets limits on the size of cells
As the surface area increases by a factor of n2, the volume increases by a factor of n3
Small cells have a greater surface area relative to volume ratio

5. Surface Area to Volume

8. Nucleus Contains most of the DNA in a eukaryotic cell
Ribosomes use information from DNA to make proteins
Nucleus contains most of the cell’s genes and usually most conspicuous organelle
Nuclear envelope encloses the nucleus, separating it from cytoplasm
Nuclear membrane is double membrane; each membrane consists of lipid bilayer

10. Nucleus Pores regulate entry/exit of molecules
Shape maintained by the nuclear lamina composed of protein
DNA and proteins form genetic material called chromatin
Chromatin condenses to form chromosomes
Nucleolus located within nucleus is site of ribosomal RNA (rRNA) synthesis

11. Ribosomes Ribosomes: made of ribosomal RNA and protein
Ribosomes carry out protein synthesis in two locations:
In the cytosol (free ribosomes)
On outside of endoplasmic reticulum or nuclear envelope (bound ribosomes)

12. Ribosomes

13. The Endomembrane System
Endomembrane system: regulates protein traffic and performs metabolic functions in cell
Components of endomembrane system:
Nuclear envelope
Endoplasmic reticulum
Golgi apparatus
Lysosomes
Vacuoles
Plasma membrane
Components are continuous or connected via vesicles

14. Endomembrane System
The endomembrane system is a complex and dynamic player in the cell’s compartmental organization

18. The endoplasmic reticulum
Endoplasmic reticulum (ER) accounts for more than half of total membrane in many eukaryotic cells
The ER membrane is continuous with the nuclear envelope
Two distinct regions of ER:
Smooth ER, lacks ribosomes
Rough ER, ribosomes studding its surface

20. Smooth VS Rough ER Smooth ER Rough ER Synthesizes lipids
Metabolizes carbohydrates
Detoxifies poison
Stores calcium
Rough ER
Bound ribosomes, secrete glycoproteins (proteins covalently bonded to carbohydrates)
Distributes transport vesicles, proteins surrounded by membranes
Membrane factory for the cell

22. Golgi Golgi apparatus: aflattened membranous sacs called cisternae
Functions
Modifies products of the ER
Manufactures certain macromolecules
Sorts and packages materials into transport vesicles

23. The Golgi

24. Lysosome Lysosome: membranous sac of hydrolytic enzymes
Can digest macromolecules
Lysosomal enzymes can hydrolyze
Proteins
Fats
Polysaccharides
Nucleic acids

25. Cell Digestive Stuff
Some types of cell can engulf another cell by phagocytosis; this forms a food vacuole
A lysosome fuses with food vacuole and digests molecules
Lysosomes also use enzymes to recycle cell’s own organelles and macromolecules, a process called autophagy

27. Concept Check Main difference between phagocytosis and autophagy?
Why are prokaryotic cells so impressive when compared to eukaryotic cells?
What are the components of the endomembrane system?
Whats the deal with skinny jeans on dudes these days?

28. Vacuoles A plant cell or fungal cell may have one or several vacuoles
Food vacuoles are formed by phagocytosis
Contractile vacuoles, found in many freshwater protists, pump excess water out of cells
Central vacuoles, found in many mature plant cells, hold organic compounds and water

30. Mitochondria & Chloroplasts
Mitochondria are the sites of cellular respiration, a metabolic process that generates ATP
Chloroplasts, found in plants and algae, are the sites of photosynthesis
Peroxisomes are oxidative organelles

31. Mitochondria & Chloroplasts
Mitochondria and chloroplasts
Are not part of the endomembrane system
Have a double membrane
Have proteins made by free ribosomes
Contain their own DNA