Class Notes (811,138)
Canada (494,513)
York University (33,712)
Biology (2,149)
BIOL 1000 (375)

BIO LECTURE 1 - light and life.docx

6 Pages
Unlock Document

York University
BIOL 1000
Paula Wilson

Introduction 9/7/2012 9:24:00 AM Light and Life – check online PowerPoint for all notes* People You Should Know: Laboratory Director – Dr. Nicole Nivillac Laboratory Coordinator – Larissa McKetton: [email protected] - Missed lab  contact TA Lab Coordinator within 24 hours at [email protected] Put “name, missed lab” in subject line office hours Wed after class, Room 108 Farq. Light and Life 9/7/2012 9:24:00 AM Themes: Unity and Diversity of Life Shape matters! Structure and Function Light Light - 2 major functions 1. Energy 2. Information Light: Electromagnetic Radiation - light is a form of electromagnetic radiation -acts like a wavelength and as a particle - variable wavelength (distance between 2 peaks) and energy  typically measured in nanometers (10^-9m)(p.F1)  wavelength and energy inversely related - different wavelengths of light have different energy - shorter wavelength ------------ higher energy - longer wavelength ------------ lower energy ^ inversely related. Light as a Particle: photon: - packet of energy with no mass - absorbed by electrons (electrons can absorb photons) Light Passing Through Matter - absorbed - reflected - transmitted Pigments: - primary function is to absorb light - common pigments have long carbon chains and alternating single and double bonds  don’t have to memorize common pigments, but should be able to tell that something is a common pigment by looking at the structure - pigments catch the energy (absorb it) Light as Energy: 1) Photosynthesis 2) Cellular Respiration * all life on the planet depends on these two processes Rhodopsin  a protein and a pigment Light as a Source of Information: - all of us rely on light as a source of information for a variety of reasons - to use light as a source of information we have to have a way of sensing it Light sensing: - photoreceptors – molecule that absorbs light and generates a response - rhodopsin: made up on opsin (pigment) + retinal (protein)  membrane bound photoreceptor How it works: shape matters!  human eye as an example in textbook Other Light Sensors: Eyespots in C. reinhardtii - also has a photoreceptor: light sensor  called phototaxis - chlamydomonas reinhardtii eyespot contains rhodopsin  flagella; which move towards or away from light Other Light Sensors: Ocelli in Planaria  flatworm as an example in textbook Simple  Complex eyes Eye spot – e.g., Euglena Eyecup – e.g., Planaria Pinhole eye – e.g., Nautilus Primitive lens – e.g., Box jellyfish Other Light Sensors: Phytochrome in Plants - phytochrome: chromophore linked to a protein  absorbs strongly in red - photomorphogenesis: gene activation Light: behavior, physiology circadian rhythms: - aspects of physiolog
More Less

Related notes for BIOL 1000

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.