BZ

Biology - SBI3U - Introduction

Levels of organization

Pre-biotic

  • Atoms

    • Smallest unit of matter

      • Cannot be broken down simpler by chemical means

  • Molecules

    • Smallest unit of most compound form by chemically bonding atom

Level of organism

  • Organelles

    • Specialized structure perform cellular function within cell

  • Cells

    • Smallest unit of life

    • Collection of living matter enclosed by barrier

      • Barrier seperates from souroundings

  • Tissues

    • Group similar cells that perform particular function

  • Organs

    • Group tissue work together perform closely related function

  • Body system/organ system

    • Group organs work together perform closely related function

  • Organism

    • Living thing composed of cells

    • Species = group organisms so similar they can breed and produce fertile offspring

Beyond individual organism

  • Population

    • Group individual of same species that live same area

  • Community

    • Group different population live together defined area

  • Ecosystem

    • Group all organism live particular place

      • Including nonliving environment

  • Biome

    • Group ecosystem that have same climate and similar dominant communities

  • Biosphere

    • Part of Earth where life exist

      • Includes

        • Land

        • Water

        • Air

        • Atmosphere

Characteristics of life

  • Composed of cells

  • Reproduction

  • Growth and development

  • Obtain and use energy

  • Respond to environment

  • DNA

  • Evolution and adaptation

Composed of cells

  • All cell come from prexist cell

  • Unicellular

    • Organism composed of singular cell

  • Multicellular

    • Organism composed many cell

    • Diversity and specialization of function

Reproduction

  • Asexual reproduction

    • Single parent copy DNA and divide genetically identical offspring

    • Can mean rapid fire reproduction of great number of identical organism

  • Sexual reproduction

    • Two parent cell unite to produce first cell of new organism

    • Offspring is genetically unique

      • Leads to genetic diversity and specialization

Growth and development

  • Unicellular organism grow mostly simple increase in size

  • Multicellular organism undergo extensive development from fertilized egg

    • Dividing many times to produce multitude of cell in mature organism

  • Differentiation = changing of shape and structure to perform a specific function

Obtain and use energy

  • Living thing obtain energy from environment

    • Use for growth, development, reproduction, excretion

      • These processes occur at different rates

  • Metabolism = combination of different chemical reaction that build and break down material as organism carry out life

    • Metabolism = anabolism + catabolism

      • Anabolism

        • Synthesizing compounds

        • Expend energy

      • Catabolism

        • Breaking compounds into single componenet

        • Release energy

Respond to environment

  • Organism detect and respond to stimulus

  • Internal stimuli

    • Happens internally

      • Like blood glucose level

  • External stimuli

    • Light, sound, touch, heat, smell, sight

  • Homeostasis = automatic process which organism respond to stimuli so condition in body is suitable to sustain life

DNA

  • DNA = universal genetic code

  • All life based on universal genetic code

    • 4 letter code

    • Determines inherited traits of all organisms

  • DNA = type of biomolecule known as nucliec acid

    • Has three dimensional shape called double helix

      • Shape allows for duplication and reading of genes it encodes

Evolution and adaptation

  • Evolution = ability of group organism change over time

    • Invaluable for survival in constant change environments

  • Adaptation = trait living thing that help it compete and survive to reproduce in environment

Biotic vs abiotic

  • Biotic = living/was once living

  • Abiotic = nonliving

Basic chemistry review

Element, molecule, compound

  • All matter made of atom

  • Atom made of proton, neutron, electron

  • Compound are made of identical compound composed 2 or more different element

Chemical bounds

  • Ionic bond

    • When exchange electron result 2 opposite charge ion which are then attracted to form a bond

  • Covalent bond

    • When 2 nonmetal share electron by overlay valence orbital electron

      • Non polar covalent = equal share

      • Polar covalent = unequal share

      • Non polar and polar covalent depend on relative strength of atom

  • Intermolecular interaction

    • Interactions that happen between molecule

    • Hydrogen bond

      • Special type intermolecular interaction

        • Hydrogen are molecule attracted to negative charge on another hydrogen

    • δ+ = slightly positive

    • δ- = slightly negative

Aqueous solution

  • Solute = substance that dissolve

  • Solvent = substance that dissolve a solute

  • Solution = substance that is result when solute dissolve in solvent

  • Like dissolve like

    • Charge substance dissolve other charge substance

    • Uncharge substance dissolve other uncharge substance

  • Concentration of solution = how much solute find per unit solvent

Extracellular vs intracellular fluid

  • Extracellular fluid = water based fluid around cell

  • Intracellular fluid = water based fluid inside cell

    • Typically refer to cytoplasm

Hydrophile vs hydrophobic

  • Hydrophilic = water loving

  • Hydrophobic = water hating

First organism

  • Archaebacteria likely first living thing

    • Were likely anaerobic and chemotrophic

      • Aerobic = need oxygen

      • Anaerobic = do not need oxygen

      • Chemotrophic = get energy by breaking down chemical compounds

    • As no oxygen and anything to consume

      • Defenitly not consumer

  • Cyanobacteria = earliest known life form in fossil record

    • Appear around 3.5 - 2.5 billion year ago

    • Evidence by stromatolites

      • Stromatolites = layered rock form by growth of microbial mat

  • How know archaebacteria first living thing

    • Phylogenetic placement

      • Position of mesophilic archaea in phylogenetic tree suggest they very old

    • Genomic data

      • Modern genomics suggest archaebacteria with relatively low level physiological complexity

    • Ancient metabolic processes

      • Presence of very ancient processes

        • Such as methanogenesis point for very old origin for archaebaceria

          • Methanogenesis = biological production of methane by methanogen, strictly anaerobic

Cell organelles

  • Organelle = little organ

  • Found only inside eukaryotic cell

  • Cytoplasm = substance between organelles

Cell membrane

  • Boundary of cell

  • Made of phospholipid bilayer

Nucleus

  • Control center of cell

  • Contain DNA

  • Surround by double membrane

  • Usually easiest organelle see under microscope

  • Usually 1 per cell

Cytoskeleton

  • Act as skeleton and muscle

  • Provide shape and structure

  • Help move organelle around cell

  • Made of three filament

    • Microtubules

      • 25nm diameter

    • Actin filament

      • 7nm diameter

    • Intermediate filament

      • 10nm diameter

Endoplasmic reticulum

  • Connected nuclear membrane

  • Highway of cell

  • Rough ER

    • Studded ribosome

    • Makes proteins

  • Smooth ER

    • No ribosome

    • Makes lipids

Ribosome

  • Site of protein synthesis

  • Attached rough ER or float free in cytoplasm

  • Produced in part of nucleus called nucleolus

  • Polypeptide = chain amino acids

    • Part of ribosome

  • Nitrogen is cirtical for build protien

Golgi apparatus

  • Store, modify, produce protien

  • Molecules transport to and from golgi apparatus by vesicle

Lysosome

  • Garbage disposal of cell

  • Contain digestive enzyme that break down waste

  • Closly work with golgi aparatus and endoplasmic reticulum

Mitochondria

  • Powerhouse of cell

  • Site of cellular respiration to release energy for cell

  • Bound by double membrane

  • Has own strand of DNA

Chloroplast

  • Only in plant cell

  • Contain green pigment cholorophyll

  • Site of glucose production

  • Bound by double membrane

  • Has own strand DNA

Cell wall

  • Found in plant and bacteria cell

  • Rigid and protective barrier

  • Locate outside cell membrane

  • Made of cellulose (fiber)

Vacuole

  • Store water, food, enzyme, waste, pigment

  • Large central vacuole usually in plant cell

  • Many smaller vacuole in animal cell

Centriole

  • Aid cell division

  • Usually found only in animal cell

  • Made of microtube like cytoskeleton