General Biology Lecture Notes

General Biology Lecture Notes - GeneralBiology

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
                                         General Biology Lecture 1: Chapter 4 – Organization of the Cell I. Cell    division)     B. Viruses are acellular because they cannot independently perform metabolic  activities     C. Cell Theory            – provides consistent explanation for all verifiable data relating to living things 1. 2. All cells come from other cells. All living cells have evolved from a common  ancestor          1. homeostasis  – appropriate internal environment          2. Plasma membrane               - surrounds the cell               - separates cell from external environment               - allows exchange of materials with environment               - allows chemical composition of cell to be different from that outside the cell          1. Measurement               -(mm) millimeter = 1/1,000 of meter = 10 -3  meter               -( m) micrometer = 1/1,000,000 of meter = 10 μ -6  meter               -(nm) nanometer = 1/1,000,000,000 of meter = 10 -9  meter               -(mm) millimeter = 1/1,000 of meter               -( m)  μ micrometer = 1/1,000 of millimeter               -(nm) nanometer = 1/1,000 of micrometer          2. Surface to Volume Ratio               -ratio of plasma membrane (surface area) to cell’s volume               -critical factor in determining cell size               -as cell becomes larger, its volume increases at a greater rate than its surface  area, decreasing surface-to-volume ratio activities               - microvilli, projections of plasma membrane, increase surface area for  absorbing nutrients                Ex . - Nerve cells need to communicate with each other; have long extensions                Ex 2 . – Epithelial cells stacked on one another become “barrier cell” e.g. skin
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 10/27/2011 for the course BIO 101 taught by Professor Martin during the Spring '08 term at Rutgers.

Page1 / 80

General Biology Lecture Notes - GeneralBiology

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online