LB145 Sec

Today’s Outline HAND IN StudyNotes3a– front of classroom. StudyNotes3b due on Thursday – see website. Minute paper (formative evaluation) Announcements The Exam What is energy? – For plants? – For animals? Why do we need energy?

Formative Evaluation What do you like about LB145? What could we do differently in LB145? Reindeer Evaluation Day at the North Pole

Announcements: Exam Return View your exam on: – Tuesday/Wednesday/Thursday 8:00am-9:00am in my office E186 – Friday 3:00pm-4:00pm in C-4. – Grades will be posted TODAY.

Exam Return: The DOs and DON’Ts DO: Check the addition. Ask yourself: Did your grade match your expectations? REFLECT – what would you have done differently to change the result? Take some time this week to review the things you did not do well at.

Exam Return: The DOs and DON’Ts DON’T: Don’t ignore your grade – a midterm exam can be a learning experience. Don’t take the ‘extra-point’ mindset.

Default Option StudyNotes Option Exams Option Midterm Exam 150 Midterm Exam Midterm Exam Final Exam StudyNotes In-Class Exercises30 Homework70 LECTURE TOTAL450 Exams67%56%78% Study Notes11%22%0% Exercises + Homework22% Flexible Grade Weightings

You must decide what option you want, fill out the form and hand it back by the end of lecture on Thursday. We will both sign the form and both get a copy of it. If you do not choose, then you will be in the default category.

If you are not doing as well as you would like to be doing… but don’t know how to fix things…

Tutorials: Friday February 8 th, 15 th 3-5pm C-3 Direct your studying, give you study problems, help you understand what you do/don’t know.

Academic Advising If you are struggling in this course – meet with an academic advisor. To make an advisement appointment with any Briggs adviser call or stop by the Lyman Briggs Office (35 East Holmes). If you have a faculty adviser, contact them directly to set up an appointment for advisement.

Where do we get our ENERGY from? Autotrophs vs. Heterotrophs

Energy and ATP On a cellular level, energy comes from the molecule ATP.

ATP Structure Campbell 8e Fig. 8.8 High energy bonds!

Hydrolysis of ATP Releases Energy Campbell 8e Fig kcal/mol

Cells use lots of energy! (in the form of ATP!)

Free Energy and Metabolism Free energy,  G = Energy available to do work  G<0 = release of energy = exergonic reaction  G>0 = consumption of energy = endergonic reaction Exergonic Δ G<0 Endergonic Δ G>0 Campbell 8e Fig. 8.6

ATP hydrolysis, an exergonic reaction, drives endergonic reactions

ATP provides ENERGY! Gotta have it… so how can you GET it?

ATP – where it comes from… Animals can only make ATP when we/they metabolize the organic material (glucose) they eat. We mostly get organic material from plants. Photosynthetic organisms make ATP when capture energy from the sun and use that energy to oxidize water.

REDOX Reactions To help us understand how energy is made in chloroplasts and in mitochondria, we need to have a working knowledge of REDOX reactions.

The Principle of Redox Chemical reactions that transfer electrons between reactants are called oxidation-reduction reactions, or redox reactions In oxidation, a substance loses electrons, or is oxidized In reduction, a substance gains electrons, or is reduced (the amount of positive charge is reduced) Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Fig. 9-UN1 becomes oxidized (loses electron) becomes reduced (gains electron)

Fig. 9-UN2 becomes oxidized becomes reduced

PHOTOSYNTHESIS!

How do plants make energy?

Photosynthesis Photosynthesis can be summarized as the following equation: 6 CO H 2 O + Light energy  C 6 H 12 O O H 2 O Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings … seems simple enough. 6 CO H 2 O + Light energy C 6 H 12 O O H 2 O

6 CO H 2 O + Light energy  C 6 H 12 O O H 2 O

Light Fig H2OH2O Chloroplast Light Reactions NADP + P ADP i + ATP NADPH O2O2 Calvin Cycle CO 2 [CH 2 O] (sugar)

The Two Stages of Photosynthesis Photosynthesis consists of the: – light reactions (the photo part) – Calvin cycle (the synthesis part) Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Fig Light Fd Cytochrome complex ADP + i H+H+ ATP P synthase To Calvin Cycle STROMA (low H + concentration) Thylakoid membrane THYLAKOID SPACE (high H + concentration) STROMA (low H + concentration) Photosystem II Photosystem I 4 H + Pq Pc Light NADP + reductase NADP + + H + NADPH +2 H + H2OH2O O2O2 e–e– e–e– 1/21/

For THURSDAY: 1.StudyNotes3b 2.Flexible Grade Weightings form (optional) 3.Molecular Sculpting: The Great Thylakoid Sculpting Competition (5 pts)

The GREAT THYLAKOID SCULPTING COMPETITION Your Task: Create a model of photosynthesis occurring in a thylakoid. Your model must include representations of: PSII, pq, the cytochrome complex, pc, PSI, fd, NADP+ reductase, ATP synthase, electrons, protons, water, NADP+, NADPH, O 2, ATP, ADP, P i You must be done by: 2:00 pm **You may use any resources you like (e.g. internet, textbook, study notes, etc.)