animal complexity

• The biological organization.

  A) cellular level

  B) atoms

  C) molecule

  D) macromolecule

  E) organelle

  F) cell

  G) tissue

  H) organs

  I) organ system

  J) organism

  
• Cellular Level - the smallest unit that can be seen with an optical microscope.
• Molecules are made up of two or more atoms chemically bonded together.
• Macromolecules are large molecules composed of many smaller units joined together by chemical bonds.
• Tissues are groups of similar cells working together to carry out a particular function.
• Organelles are specialized structures within cells that perform specific functions.
• The human body contains around 200 different types of cells, which are categorized into four tissue types:

  • Connective tissue
  • Muscular tissue
  • Epithelial tissue
  • Nervous tissue
• Relative sizes on a logarithmic scale

  A) logarithmic scale

  B) 10 micrometer

  C) 100 micrometer

  D) light microscope

  
• Cellular level is the smallest unit of life that can be seen with a light microscope.
• In 1665, Robert Hooke, a renowned British scientist, published his book "Micrographia," where he described his observations of various objects under a microscope, including a thin slice of cork. Through his observations, he saw tiny compartments resembling the cells of a monastery and later on Hooke coined the term "cell" to describe them. This discovery revolutionized the way scientists viewed the natural world and laid the groundwork for the development of cell theory, which states that all living organisms are composed of cells.
• During the 17th century ( 1673 - 1683 ) - a Dutch scientist, Anton van Leeuwenhoek, also known as the "father of Micobiology" renowned for his groundbreaking contributions to the field of microbiology. Van Leeuwenhoek designed and built simple microscopes that allowed him to achieve unprecedented levels of magnification. Using these microscopes, he made numerous significant discoveries, including the observation of bacteria, protozoa, and sperm cells. One of his notable achievements was his discovery of single-celled organisms, which he called "animalcules."
• THE CELL THEORY

  • in the year 1838 – Matthias Schleiden – all plant parts are made of cells

  
  

  • in the year 1839 - Theodore Schwann – wrote the first part of the cell theory.

  o All organisms are composed of one or more cells.

  o The cell is the basic unit of life in all living things.

  
  

  • in the year 1858 – Rudolf Virchow – wrote the third part of the cell theory

  o All cells come from existing cells
• PROKARYOTES

  • The way their DNA is packaged

  – No nucleus - A membrane-bound organelle in that contains the cell's chromosomes

  – Not wrapped around histones ( a protein that provides structural support for the chromosomes )

  • The makeup of their cell wall

  – Bacteria- have peptidoglycan

  – Archaea - tough and made of other chemicals, distinct to them

  • Their internal structures

  – they don't have complex, membrane-bound organelles
• Prokaryotes are unicellular organisms without a true nucleus, while eukaryotes are multicellular organisms with a true nucleus.
• The main difference between prokaryotes and eukaryotes is the presence of a true nucleus in eukaryotes. Prokaryotes lack this structure, instead having their genetic material floating throughout the cytoplasm. Eukaryotes also have larger, more complex cells than prokaryotes, containing multiple membranes and specialized organelles such as mitochondria and chloroplasts.
• label the parts of this prokaryotic cell

  A) glycocalyx

  B) bacterial chromosome

  C) plasmid

  D) pilus

  E) ribosomes

  F) actin skeleton

  G) flagellum

  H) fimbriae

  I) inclusion

  J) cell wall

  K) cell membrane

  L) outer membrane

  M) endospore

  N) cytoplasm

  
• what are the 3 regions of the prokaryotic cell? enumerate the structure from each region

  • external region
  • flagella
  • pili
  • fimbriae
  • glycocalyx
  • cell envelope region
  • outer membrane
  • cell wall
  • cell membrane
  • internal region
  • cytoplasm
  • ribosomes
  • inclusions
  • plasmid
  • bacterial chromosomes
  • actin skeleton
  • endospore
• Glycocalyx (pink coating)—A coating

  or layer of molecules external to the cell wall. It serves protective, adhesive, and receptor functions. it may fit tightly or be very loose and diffuse.
• Flagella (green wavy lines) — Long, whip-like appendages used by bacteria for movement. They consist of a long filamentous sheath surrounding a central core of microfilaments called axonemes. Flagella rotate rapidly at the base, causing the entire length of the flagellum to move back and forth like a propeller.
• Fimbriae (blue short lines) — Small, hair-like appendages used by many bacteria for attachment to surfaces. Fimbriae are often found in clusters on the surface of the cell.
• Pilus (red hairy line) - A short, flexible appendage that allows some bacteria to attach themselves to other surfaces. Pilus can be involved in conjugation, which is the transfer of DNA from one bacterium to another.
• Bacterial chromosome or nucleoid - Composed of condensed DNA molecules. DNA directs all genetics and heredity of the cell and codes for all proteins.
• Plasmid — a small, circular shape, double-stranded DNA molecule that is distinct from a cell's chromosomal DNA. Plasmids naturally exist in bacterial cells, and they also occur in some eukaryotes. Often, the genes carried in plasmids provide bacteria with genetic advantages, such as antibiotic resistance.
• ribosomes - are tiny, spherical organelles that are made up of RNA and proteins and are responsible for protein synthesis. They are compact structures that are widely distributed in the cytoplasm of prokaryotic cells and can float freely or be attached to the rough endoplasmic reticulum.
• Actin cytoskeleton - Long fibers of proteins that encircle the cell just inside the cell membrane and contribute ot the shape of the cell.
• Inclusion/Granule -Stored nutrients such as fat, phosphate, or glycogen deposited in dense crystals or particles that can be tapped into when needed.
• Cell wall — A semirigid casing that provides structural support and shape for the cell.
• Cell membrane -A thin sheet of lipid and protein that surrounds the cytoplasm and controls the flow of materials into and out of the cell pool.
• Outer membrane - Extra membrane

  similar to cell membrane but also containing lipopoly-saccharide. Controls flow of materials and portions of it are toxic to mammals when released.
• Endospore - are dormant, tough, non-reproductive structures that some prokaryotic cells can form to survive in unfavorable conditions. The process of forming endospores is called sporulation and can be triggered by stress like UV radiation, high temperatures, harsh chemicals, or a lack of nutrients. 
• Cytoplasm - a water based solution( 70% to 80% water) filing the entire cell where most of the biochemical reactions take place. it is also a location for growth, metabolism, and replication
• Peptidoglycan is a huge polymer of interlocking chains of alternating monomers.

  Backbone of peptidoglycan molecule composed of two amino sugar derivatives of glucose. The “glycan” part of peptidoglycan:

  • N-acetylglucosamine (NAG)
  • N-acetlymuramic acid (NAM)
• Plasma Membrane - Separates the cell from its environment

  • Phospholipid bilayer with proteins embedded in two layers of lipids (lipid bilayer)
• the goal of antibiotic in our bodies is to eradicate bacteria specifically to disrupt the cell wall, and cells have little protection from lysis

  • Gram-positive cell (2 layers) – A thick (20 to 80 nm) peptidoglycan cell wall and membrane
  • Gram-Negative Cell (3 layers) – Outer membrane – Single, thin (1 to 3 nm) sheet of peptidoglycan
• lysis refers to the breakdown of a cell caused by damage to its plasma (outer) membrane
• types of peptidoglycan

  A) gram positive

  B) peptidoglycan

  C) cell membrane

  D) gram negative

  E) cell membrane

  F) peptidoglycan

  G) outer membrane

  
• The Gram stain uses four stains/reagents: crystal violet, Gram's iodine, ethanol, and safranin. Crystal violet (the primary stain), enters the peptidoglycan of all bacteria giving them a purple color.
• Prokaryotic reproduction

  • binary fission - this process involves copying the chromosome and separating one cell into two – asexual form of reproduction
  • transformation - the prokaryote takes in DNA found in its environment that is shed by other prokaryotes.
  • transduction - bacteriophages, the viruses that infect bacteria, sometimes also move short pieces of chromosomal DNA from one bacterium to another
  • Conjugation - DNA is transferred from one prokaryote to another by means of a pilus
• prokaryotic reproduction

  A) binary fission

  B) transformation

  C) transduction

  D) conjugation

  
• A prokaryote is a single-cell organism whose cell lacks a nucleus and other membrane-bound organelles. This includes the archaea, and eubacteria