3/27 Daily Catalyst Pg. 41 Into to transport 1. Mrs. Ireland gives you a mystery cell and asks you to find out what type of cell it is. You look under the microscope and see there is a cell wall. What type of cell did Mrs. Ireland give you? 2. Why are prokaryotes more susceptible to mutations versus eukaryotic cells? 3. A population in HWE, has 34% of the population exhibiting hybrid characteristics. Calculate the percentage of the population with the dominant allele.

3/27 Daily Catalyst Pg. 41 Into to transport Transport quiz #10 on Wednesday If you will not be here, you must take the quiz TUESDAY Transport lab next Mon.- Wed. Please be here. Labs are test grades Notebook check next Wednesday Quiz tracker, table of contents, and notes Spring Break packet due Tuesday, 4/7

3/27 Daily Catalyst Pg. 41 Into to transport Class Business Prokaryote notes Quiz #9 Intro to transport Membranes

Pg. 40 - Prokaryotic DNA Key Point #3: Prokaryotic DNA Circular DNA Located in the nucleoid region Double stranded Limited genetic information Key Point #4: Plasmids Smaller rings of DNA Replicate independently Shared between bacteria

The ribosome is similar in both prokaryotes and eukaryotes The ribosome is similar in both prokaryotes and eukaryotes. In prokaryotes, ribosomes are smaller and fewer in number. Another type of antibiotics, Erythromycin and tetracycline, bind to ribosomes and block protein synthesis in prokaryotes, but not in eukaryotes.

Turn and Talk How do bacteria reproduce? How does this form of reproduction add bacteria in their evolution (think back to the evolution of bacteria resistance).

Reproduction and adaptation Key Point #5: Divide by binary fission Reproduce quickly Make exact replicas (clones) Bacteria can replicate so quickly as in 1-3 hours. Some can replicate as quickly as 20 minutes. But there is a lack of energy and nutrients so that is why Bacterium has not taken over the world. Endospores form to protect the DNA.

Prokaryotes can adapt quickly to changes in their environment through evolution by natural selection. Because of prokaryotes’ rapid reproduction, mutations that confer greater fitness can swiftly become more common in a population.

Where else have we seen prokaryotes? Think back to ecology! Bacteria convert atmosphere nitrogen (N2) into ammonia (NH3), a process called nitrogen fixation (nitrogen cycle). The ammonia is used for amino acids (building blocks) and other organic molecules.

We have only characterized only 4,500 species of bacteria while a single handful of dirt can contain over 10,000 species of bacteria. Yes, this will take a lot of time to classify!

Pathogens Prokaryotes cause about half all of human disease 2-3 million people have died from TB Pest-carried disease is Lyme Disease Antibiotic resistance! Resistance quickly passes throughout populations

Not all bacteria are bad! When do we use bacteria for good? Convert milk to cheese and yogurt Gene cloning and E. Coli Transgenic plants Venter and designing a prokaryotes that can perform specific tasks Hydrogen for energy

In your notes on Pg. 40 Textbook page 316 Property Description Pill shape, spiral, spherical Cell size Cell surface ___________ and __________ flagella Membranes bound organelles?? Genetic information Circular DNA and ________________ Reproduction and growth

In your notes on Pg. 40 Property Description Cell shape Pill shape, spiral, spherical Cell size unicellular Cell surface Capsule and pili Motility flagella Membranes bound organelles?? No membrane bound organelles Genetic information Plasmids and circular DNA Reproduction and growth Binary fission

Partner Review The 4 scientists involved with the cell theory Major organelles discussed today

Quiz #9 Directions: Silently and independently complete the quiz. Turn your quiz into the basket when you are finished. Noise: 0 (SILENT) Time: 15 minutes

Monday, we will compare and contrast active and passive transport. 3/27 Objective Today we will observe the construction of the plasma membrane and how the structure allows the membrane to be semi-permeable. Monday, we will compare and contrast active and passive transport.

Key Concepts 1. Membrane structure results in selective permeability 2. Cellular membranes are fluid mosaics of lipids and proteins 3. Membranes are fluid structures

Overview What is transport? Definition: to carry goods from one place to another Overview: Life at the Edge The plasma/cell membrane Is the boundary that separates the living cell from its nonliving surroundings Key Point #1: The cell membrane regulates what enters and leaves the cell Nickname? Goods are moved around the cell with the help of membranes. The main transporter is the cell membrane.

Membrane structure results in selective permeability The ability to discern what enters and leaves the cell is described as __________ _____________ The plasma membrane exhibits selective permeability Key Point #2: Selective permeability: some substances are allowed to cross and others are not Selective Permeability

How is the membrane SOOO selective? Structure duh! Turn and talk Discuss with a partner the structure of the cell membrane. USE KEY WORDS! Structure duh! Have a two students come up front and teach the class what they know about phospholipids.

Cellular membranes are fluid mosaics of lipids and proteins Key Point #3: The cell membrane is composed of phospholipids Hydrophobic tail Hydrophilic head Key Point #4: Amphipathic Amphi: Both Pathic: To have/posses Another term we give to cell membranes is amphipathic

Scientists studying the plasma membrane APPLICATION A cell membrane can be split into its two layers, revealing the ultrastructure of the membrane’s interior. TECHNIQUE Extracellular layer Proteins Cytoplasmic layer Knife Plasma membrane These SEMs show membrane proteins (the “bumps”) in the two layers, demonstrating that proteins are embedded in the phospholipid bilayer. RESULTS Figure 7.2 Hydrophilic head Hydrophobic tail WATER

Cellular membranes are fluid mosaics of lipids and proteins Key Point #5: The fluid mosaic model: A membrane is a fluid structure with a “mosaic” of various proteins embedded in it

Protein Type #1 Key Point #6: Integral proteins Transmembrane proteins spanning the membrane Figure 7.8 N-terminus C-terminus a Helix CYTOPLASMIC SIDE EXTRACELLULAR SIDE Alpha helices

Protein Type #2 Key Point #7: Peripheral proteins Loosely bound to the surface of the membrane Act as an “appendage” Both attach themselves to the ECM and cytoskeleton. They function in cell to cell communication.

Membranes are fluid structures Membranes are not static sheets locked rigidly in place. Key Point #8: Held together by hydrophobic interactions Very weak TRY IT!

The Fluidity of Membranes Phospholipids in the plasma membrane Can move within the bilayer Lateral movement (~107 times per second) Flip-flop (~ once per month) (a) Movement of phospholipids

Membranes are fluid structures Membranes are not static sheets locked rigidly in place. Key Point #8: Held together by hydrophobic interactions Very weak

It all comes back to Selectively Permeable Read page 24, 2.9 Answer in your notes: Define polar: Example of a polar molecule: Draw an example of this polar molecule: On page 86, answer 3 and 13