Class Notes (834,812)
Canada (508,731)
HSCI 100 (134)
Lecture

week2 - chp3.docx

4 Pages
134 Views
Unlock Document

Department
Health Sciences
Course
HSCI 100
Professor
Nienke Van Houten
Semester
Summer

Description
Chapter 3: the cell PROKARYOTIC CELLS EUKARYOTIC CELLS (third domain of life) - First cells to evolve - Nucleus that has DNA - Lacks nucleus - Membrane bound organelles - Represented by bacteria & archaea - Plants, animals, fungi, protists - Circular DNA in cytoplasm - Coiled, linear DNA - cytoskeleton - cytoskeleton SURFACE TO VOLUME RATIO - as cell gets larger, SA increases much more slowly than volume o nutrients enter cell and waste leaves @ surface  larger cell difficulty moving nutrients across inadequate surface  would not survive PLASMA MEMBRANE - functions o boundary between internal/ext enviro o selectively permeable o cell-cell recognition  recognize glycoproteins – foreign invaders like bacteria o communication between cells  receptors o binding pairs/group of cells together  cell adhesion molecules (CAMs)  stick cells together to form tissues and organs - fluid mosaic model o cholesterol as support o carbohydrates on proteins & lipids on the outer layer o selectively permeable – allows some things in, keeps other substances out - structure o hydrophilic heads face outside cell interact with extracellular fluid o hydrophilic heads facing inside interact with cytoplasm o hydrophobic tails point toward and hold membrane together MEMBRANE TRANSPORT 1. Diffusion - Random move from higher concentration to lower concentration - Passive transport (doesn’t require energy) - Concentration gradient: difference in relative number of molecules/ions in given substance in two adjacent areas 2. Facilitated diffusion - Doesn’t require energy - Water soluble substances repelled - Carrier proteins bind to water-soluble substance - With concentration gradient - Protein channel carries particles through 3. Osmosis (cross through protein) - Water moves from higher h2o concentration to lower - Hypo/hypertonic 4. Active transport - Carrier protein + energy from ATP - Against concentration gradient (lower concentration to higher) - Na+/K+ pump – bodies have higher potassium, lower sodium - Sodium out/Potassium in 5. Exocytosis - Fusion of vesicle with plasma membrane - Transports molecules outside cell 6. Endocytosis - Transports molecules inside cell - Invagination of plasma membrane to form vesicle - Membrane pinches in and forms vesicle that brings substances in TONICITY: - Hypertonic – more solute than inside of cell o Water flows out of cell o Cell shriveling - Hypotonic – less solute than inside of cell o More water outside – water flows into cell o Cell swelling/burst - Isotonic – solutions equal amounts of solute inside & outside of cell. No effect ORGANELLES – discrete compartments that work together - Nucleus o Function:  Contains DNA and controls cell activity  separates genome/dna from cytosol, transcription from translation o Structure:  Nuclear envelope - Double membrane surrounds nucleus and separates from cytoplasm (nuclear envelope)  Nuclear pores – communication between nucleus and cytoplasm  Chromosomes – threadlike structures made of DNA and associated with proteins  Nucleolus – specialized region in nucleus  Forms an
More Less

Related notes for HSCI 100

Log In


OR

Join OneClass

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

Sign up

Join to view


OR

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.


Submit