Zoology

September 1st

What is Life?

  • A living organism

  • Have cells

  • can reproduce

Define the 7 properties of living organisms

  • Reproduction: getting DNA from parents, which can occur either sexually or asexually depending on the species.

  • Evolutionary adaptation

  • Response to the environment: smells food, senses danger

  • Regulation: Maintaining homeostasis, maintaining a stable environment, regulating body temperature

  • Order: Opposite of chaos

  • Growth and development: speaks for itself..

  • Energy processing: Living takes work you have to eat and take things like sugar

5 things of Biology

  • organization:

    • Composed of building blocks - Biomolecules

    • Structures inside - Organelles (chloroplast) (nucleus)

    • Maintaining internal environment - Cells

    • Groups of cells that have a purpose - Tissue

    • Has a purpose to keep you alive - Organs and organ systems

    • have you itself - Organism

    • Multiple individuals of the same species - Populations

    • Individuals from many species - Communities

    • Abiotic aspects things like water, air, sunlight - Ecosystems

    • The Whole Earth - The Biosphere

  • Information

    • Genetic material in the form of DNA (deoxyribonucleic acid)

    • Double helix: the structure of DNA, consisting of two intertwined strands that coil around each other, forming a stable and efficient framework for transmitting genetic information.

    • Genes: segments of DNA that contain the instructions for building proteins, which determine the traits and functions of an organism.

    • DNA controls the development and maintenance of organisms

    • Human: Half clone of each parent

    • Gene expression: process from information code to the final product

    • DNA: transcription

    • mRNA: Translation

    • Chain of amino acids: Protein folding

    • = Protein

  • Energy and matter

    • Plants have to get sunlight, humans have to eat things..

    • The input and transformation of energy from the sun and energy rich biomolecules makes life possible

    • Energy flow from organism to organism

  • Interactions:

    • Organisms also interact with each other and the environment is affected by the organisms living there

  • Evolution:

    • Evolution is the one unifying idea that makes logical sense of everything we know about living organisms

    • “Nothing in biology makes sense except in the light of evolution”

    • “Descent with modification” Charles Darwin, The origin of species (1859)

In feedback regulation the output or product of a process (negative feedback) or amplify and intensify it (positive feedback) Ex: (Stimulus) high blood glucose level

  • Response: Glucose uptake by liver and muscle cells (negative feedback)

Grouping Species: Taxonomy

  • Taxonomy is the branch of biology that names and classifies species into groups of increasing breadth (Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species)… DKPCOFGS

Mechanisms of evolution: Natural Selection, Genetic Drift, and Gene Flow are key processes that influence the evolution of species by altering allele frequencies within populations.

Lecture - Thursday Sep 3rd

The Chemical Context of life

  • Organisms are composed of matter:

  • Matter is anything that takes up space and has mass. Matter is made of elements

  • An element is a substance that cannot be broken down to other substances by chemical reaction

  • A compound is a substance consisting of two or more elements in a fixed ratio. A compound has characteristics different from those of its elements

Example of Emergent Properties in Compounds:

  • Sodium (NaNa): A soft, silvery, highly reactive metal that reacts violently with water.

  • Chlorine (Cl2Cl_2): A toxic, poisonous yellow-green gas.

  • Sodium Chloride (NaClNaCl): Combining sodium (NaNa) and chlorine (Cl2Cl_2) in a 1:11:1 ratio forms edible table salt, which is harmless and essential for life.

  • Emergent Properties: The resulting compound (NaClNaCl) exhibits completely new chemical and physical properties distinct from those of its individual constituent elements.

Each element consists of unique atoms

An atom is the smallest unit of matter that still retains the properties of an element

Atoms: are composed of subatomic particles including:

  • Electrons (negative charge)

  • Protons (positive charge)

  • Neutrons (no electrical charge)

1) Protons and neutrons are in the nucleus

2) Electrons (negative charge) orbit around the nucleus in defined energy levels.


Atoms of the various elements differ in number of subatomic particles

An elements atomic number is the number of protons in its nueclous

AN = P

An elements mass number is the sum of the number of protons and neutrons in its nucleus, which gives an indication of the isotope of the element.

M = P+N


Isotopes

Differ in # of neutrons. Same # of protons

C^12 / C^13 / C^14

Radioactive Isotopes

  • are often used as diagnostic tools and imaging in medicine (thyroid cancer)

  • Can be used approximate dates of specimens (fossils etc)


The energy is the capacity to cause change

Potential energy is the energy that matter has because of its location or structure

The electrons of an atom differ in their amounts of potential energy

An electrons state of potential energy is called its energy level, or an electron…


Valence electrons are those in the outermost shell, or valence shell

The chemical behavior of an atom is mostly determined by the valence electrons

Elements with a full valence shell are chemically inert

  • Rows / columns of periodic table

An orbital is the three dimensional space where an electron is found 90% of the time


Chemical Bonds:

Covalent bonds form when atoms share two or more valence electrons

  • Sharing/loving bonds

Ionic bonds are formed by the attraction of oppositely charged ion

  • Greedy/stealing bonds

1) Contrast ionic and covalent bonds with respect to

a) their relative stability/strength

b) their uses in the human body


A cation is a positive charged ion

An anion is a negative charged ion

An ionic bond is an attraction between a cation and a anion


Molecules are groups of atoms held together in a stable association

Compounds are molecules containing more than one type of element


Hydrogen Bonds

A hydrogen bond forms when a hydrogen atom covalently bonded to one electronegative atom is also attracted to another electronegative atom