biology quiz 1

• Robert Hooke coined the term "cells"
• Anton van Leeuwenhoek was the Father of Microbiology and the first to discover microbes in a fly's eye
• Robert Brown was a botanist who discovered the nucleus
• Matthias Schleiden hypothesized that a plant cell would grow as an individual unit due to the nucleus
• Rudolf Virchow reasoned that every cell comes from preexisting cells
• Theodore Schwann discovered that both plants and animals are made up of cells
• Unified Cell Theories:

  • The cell is the basic structural and functional unit of living things
  • Every organism is made up of cells
  • Cells come only from preexisting cells
• Plasma Membrane:

  • Thin, outermost membrane that maintains the cell as a distinct entity
  • Made up of a phospholipid bilayer
• 3 Basic Components of Cells:

  • Plasma Membrane or Cell Membrane
  • Cytoplasm
  • Nucleus or Nucleoid
• Cytoplasm:

  • Semi-fluid matrix found between the plasma membrane and the nucleus
  • Where organelles are suspended
• Nucleus:

  • Membrane-bound sac which contains the DNA
  • Contains DNA which contains instructions for building proteins
  • Has 2 functions:

  a. Separate DNA from the rest of the cell parts

  b. Outer membrane regulates passage of materials
• Parts of the Nucleus:

  1. Nuclear Envelope:

  • Consists of 2 lipid bilayers
  • Has pores (nuclear pores)
  • Controls passage of substances in and out of the nucleus

  2. Nucleolus:

  • Contains a dense cluster of RNA and proteins
  • Construction site wherein ribosomal subunits are made

  3. Nucleoplasm:

  • Fluid interior of the nucleus

  4. DNA:

  • Chromatin is the cell's collection of DNA
  • Chromosome is a single DNA molecule with its proteins
• Robert Hooke discovered cork cells, which he called "cellulae" meaning small rooms
• Anton van Leeuwenhoek is known as the Father of Microbiology and developed Leeuwenhoek's Microscope
• René Joachim Henri Dutrochet:

  • French physician and botanist
  • One of the first to conclude that various parts of organisms are made up of cells
  • Discovered osmosis
• Robert Brown:

  • Observed Brownian movement
  • Noted that cells contain a large central part or nucleus, which he called "little nut"
• Félix Dujardin:

  • French zoologist
  • Reported that cells are not hollow, empty structures but are full of a clear, jellylike fluid called cytoplasm
• Matthias Schleiden:

  • German botanist
  • Stated that "All plants are made of cells"
• Theodore Schwann:

  • German zoologist
  • Stated that "All animals are made up of cells"
• Rudolf Virchow:

  • German physician
  • Coined the phrase "Omnis cellula e cellula" meaning "All cells come from pre-existing cells"
• James Watson and Francis Crick:

  • Watson is an American biologist, Crick is a British biophysicist
  • Discovered the double helix structure of DNA
• Rosalind Franklin and Maurice Wilkins:

  • British biophysicists
  • Produced images of DNA using x-ray diffraction, indicating the helical shape of DNA
  • Their photographs were used by Watson and Crick to determine the detailed structure of DNA
• Jan Evangelista Purkyne, also known as Purkinje:

  • Discovered blood plasma and protoplasm
  • First to use a microtome
• Prokaryotic Cell
• Parts of a Prokaryotic Cell:

  • Capsule:

  * Present in most pathogenic bacteria

  * For protection

  • Cell Wall:

  * Supports the cell and imparts shape

  • Plasma Membrane:

  * Permeable to dissolved substances

  • Cytoplasm:

  * Tiny volume

  * Contains ribosomes

  • Nucleoid:

  * Region which contains the bacterial DNA

  • Flagella/Cilia:

  * For locomotion
• Eukaryotic Cell
• Common Parts of a Eukaryotic Cell:

  • Organelles:

  * Internal, membrane-bound sacs

  * Functions:

  1. Compartmentalization

  2. Allow interconnected reactions to proceed at different times
• Organelles:

  • Rough Endoplasmic Reticulum
  • Smooth Endoplasmic Reticulum
• Endoplasmic Reticulum:

  A. Rough ER (RER):

  * Continuous with the nuclear envelope

  * Stack of flattened sacs

  * Contains ribosomes, which synthesize proteins

  B. Smooth ER (SER):

  * Free of ribosomes

  * Curved like pipes

  * For lipid assembly

  * Packaging center

  * Modifies, sorts and packages materials in vesicles for export or for cell use

  * Golgi Bodies
• Types of Golgi Bodies:

  1. Lysosomes:

  • Organelles of internal digestion
  • 'Suicidal bag' of the cell

  2. Peroxisomes:

  • Breakdown fat and amino acids
• Vacuoles

  Mitochondria:

  * Powerhouse of the cell: forms ATP

  * Contains an inner membrane, which is highly convoluted forming infoldings called cristae

  Cytomembrane System
• galileo galilei - insects eye
• CELL CYCLE - the sequence of activities in cells during their development involving alternate division and ‘resting stage’
• INTERPHASE ⚫ Cells are said to be ‘inactive’ or ‘resting’ ⚫ Undividing ⚫ stage A period of diverse activities ⚫ Cells synthesize RNA, proteins and grow in size ⚫ In mammalian cells, it lasts 12 24 hours
• 1. INTERPHASE - Cells are said to be ‘inactive’ or ‘resting’ ⚫ Undividing ⚫ stage A period of diverse activities ⚫ Cells synthesize RNA, proteins and grow in size ⚫ In mammalian cells, it lasts 12 24 hours