Biology 160 Are we really what we eat? Today: (5 min) Scientists at work! Review from yesterday (10 min) Safety (1 hr 30 min) Lab 01! (10 min) Break (10 min) Class website and Discussion assignment (10 min) small group discussion Reading Guide 02 Any questions you had? Share what cell city jobs you picked and WHY Quiz each other on the cellular structures (20 min) whole class review on cells and cell structure (10 min) small group cell structure activity

Class Website

The difference between an observation and an inference A verifiable description or measurement An educated guess based on observations or prior knowledge Could an inference be incorrect? How would you test it?

Scientists at Work! Observations (looking carefully) Observed fibers, veins, color, shape, parts of foods, water upon cutting We’ll make a list of what kind of observations we might make for Lab 01 Prior knowledge (experience) Digestive system breaks down food and distributes nutrients to body. Onion becomes sweet after cooking and makes you cry. DNA found in nucleus of cells These unprocessed foods are made out of plant cells Proteins, carbs, and lipids are in foods Inferences (educated guess) Carbs are inside the potato, carbs and protein form the flesh of the red pepper, proteins are in the skin of the carrot, lipids and proteins might be found inside sweet potato, but where?

Am I Really What I Eat? continued… Next we’ll start to prepare ourselves to answer the question, “What does my food look like under the microscope?” Today we’ll learn how to use a microscope in Lab 01 Next week we’ll look at our food more closely in Lab 02 using this revolutionary tool!

Biology 160 Are we really what we eat? Today: (5 min) Scientists at work! Review from yesterday (10 min) Safety (1 hr 30 min) Lab 01! (10 min) Break (10 min) Class website and Discussion assignment (10 min) small group discussion Reading Guide 02 Any questions you had? Share what cell city jobs you picked and WHY Quiz each other on the cellular structures (20 min) whole class review on cells and cell structure (10 min) small group cell structure activity

The Three Domains of Life The three domains of life are: Bacteria Archaea Eukarya Prokaryotes Eukaryotes

The Three Domains of Life The three domains of life are: Bacteria Archaea Eukarya Prokaryotes Eukaryotes At least four kingdoms of Eukarya Plantae Fungi Animalia Protists (a group of multiple kingdoms)

Biology 160 Are we really what we eat? So far, what evidence do we have to support or refute this question?

Cells! The cell is the lowest level of structure that can perform all activities required for life. Cell Theory: All living organisms are composed of cells. All cells come from other cells. We can distinguish two major types of cells: Prokaryotic Eukaryotic Photo source: Wikipedia

The prokaryotic cell is simple, small, and contains no organelles. The eukaryotic cell is larger and more complex and contains organelles.

Prokaryotic and Eukaryotic Cells: Two typical kinds of eukaryotic cells: - Animal cells - Plant cells (DNA) (DNA) Cytosol Cytosol A prokaryotic cell

Prokaryotic and Eukaryotic Cells: What do all cells have in common? (DNA) (DNA) Cytosol Plasma membrane Cytosol Ribosomes Cytosol Chromosomes made of DNA A prokaryotic cell

Plasma Membrane The plasma membrane separates the living cell from its nonliving surroundings. - Allows cell to interact with environment - Regulates traffic into and out of the cell

Cell Surfaces Plant cells and bacterial cells have cell walls, Which help protect the cells, maintain their shape, and keep the cells from absorbing too much water.

Cell Surfaces Animal cells have an extracellular matrix and cell junctions, Which helps hold cells together in tissues and protects and supports them (not shown). Try giving your skin a good pull. If your skin is made out of cells, how do they all stick together? Extracellular matrix and junctions!

The Nucleus: Genetic Control of the Cell The nucleus is the manager of the cell. Genes on the DNA in the nucleus store information necessary to produce proteins. Prokaryotes do not have nuclei. Their genes (on DNA) are in the nucleoid region

How DNA Controls the Cell DNA controls the cell by transferring its coded information into RNA. The information in the RNA is used to make proteins.

The Endomembrane System: Manufacturing, Distributing, and Storing Cellular Products Not found in bacterial cells!

Smooth ER The smooth ER lacks the surface ribosomes of rough ER and produces lipids, including steroids.

Rough ER The “roughness” of the rough ER is due to ribosomes that stud the outside of the ER membrane. The functions of the rough ER include: Producing two types of membrane proteins Membrane proteins Secretory proteins Producing new membrane

After the rough ER synthesizes a molecule, it packages the molecule into transport vesicles. These vesicles head off to the Golgi Apparatus…

The Golgi Apparatus The Golgi apparatus Works in partnership with the ER. Refines, stores, and distributes the chemical products of cells.

Lysosomes A lysosome is a membrane-enclosed sac that contains digestive enzymes to break down macromolecules.

Vacuoles Vacuoles are membranous sacs. Contractile vacuoles of protists get rid of excess water. Central vacuoles of plants store nutrients, absorb water, contain some pigments or poisons.

A review of the endomembrane system An amazing system that manufactures, distributes, and stores cellular products!

Energy Conversion: Chloroplasts & Mitochondria Cells require a constant energy supply to do all the work of life. Not found in bacterial cells!

Chloroplasts Chloroplasts are the sites of photosynthesis, the conversion of light energy to chemical energy. All little green circles are chloroplasts Cell walls

Mitochondria Mitochondria are the sites of cellular respiration, which involves the production of ATP from food molecules.

The Cytoskeleton: Cell Shape and Movement The cytoskeleton consists of a network of fibers. Also, recently found in bacterial cells!

Cytoskeleton Can change cell shape to allow movement Mechanical support to maintain cell shape

Cilia and Flagella Cilia and flagella are motile appendages. Not found on most plant cells!

Flagella propel the cell in a whiplike motion. Cilia move in a coordinated back-and-forth motion.

Plastids Membrane-bound organelles found only in plants Amyloplast stores starch (stained blue with iodine) All little green circles are chloroplasts Chromoplast stores pigments (little orange circles) Cell walls Chloroplast performs photosynthesis

Are we really what we eat? What do you think? What is your evidence? What do we need to learn more about?