Chapter 1: C&G

What is biology? The study of life/living things.


What is science? An active, empirical search

  • Capital “S” science → law of gravity

  • Lowercase “s” science → real science

  • Emipricial means DATA


Shared characteristics of LIFE

  1. Cell(s)

  2. Metabolism

  3. Reproduction

  4. Growth/Development

  5. Environment 

True or False: Viruses are living. False, viruses are aliving, NOT alive

Life Requires Energy

What is the main source of energy? Solar fusion

How much of Earth’s energy does solar fusion create? 99.97%

Solar fusion creates all __________ occurring elements? Naturally

Chemical Elements

Element- a substance that cannot be broken by chemical reactions.

All atoms of elements share characteristics

Taking one element, and using it with another element, you get what? A compound

With compounds, you get ______ properties. Emergent 


Major components of the body

  1. Oxygen (O)

  2. Carbon (C)

  3. Hydrogen (H)

  4. Nitrogen (N)


Trace Element

Trace elements are very small elements that are still essential to the human body.

An example of a trace element is iodine


Deeper Understanding of Iodine

The source of iodine is? Salt

Natural way of iodine? Seafood

Why is iodine important? Without iodine, a patient can develop goiter.


Deeper Understanding of Goiter Condition

What is a goiter? Enlargement of the thyroid gland that produces T3 and T4.

Symptoms of goiter? Red, puffy, and bulging eyes.


Biology View of the Thyroid

Thyroid colloid → pumps a protein called thyroid globin and iodine.

T3 and T4 helps with fat metabolism, body temperature, etc.


The Atom

Three major subatomic particles

  1. Proton (positively charge)

  2. Neutron (neutrally charged)

  3. Electron (negatively charged)


What is composed in the nucleus? Protons and neutrons.


What two particles make up the atomic number? Just protons.


What two particles make up atomic mass? Protons and neutrons. 


Isotopes have the same atomic number, but a different atomic mass.



Beta-minus decay is the releasing of an electron (atomic number is changing).

  • When you release an electron, the atomic number increases. 


PET Scan

Positron Emission Tomography (PET)- detecting the release of positrons (positively charged electrons).

Where do the positrons come from? The health care provider puts it in the patient.

What consists of what they put in the patient? FDG (Glucose minus oxygen, plus the fluorine)

Fluorine is radioactive.

What is FDG usually used for? Cancer, the cancer thinks its glucose, the positrons become released, and they can detect the tumor.


(Continued) Positron Emission Tomography (PET) Scan

18F-FDG (fluorine) 18 undergoes beta-plus decay

Equation (insert here) 


What is FDG used for? Specifically, and commonly used with detecting cancer (tumor)

  • Black, dark splotches on PET scan means that positrons detected 

  • Positrons mean what on a PET scan? That cancer is detected in the body.

  • Radio decay detects positrons 

  • Tumors love glucose, more glucose transfers to the tumor


Practice Exam Problem

WRITE THIS IN FREE TIME


Energy Levels of Electrons (Next topic) 

Valence electrons are the number of electrons in outermost shell

  • Two electrons needed in innermost shell

  • Eight electrons needed in the outermost shell


Bonding(s)

Covalent bonding (strongest bond) is the sharing of electrons (strongest bond).

      → Electronegativity and Polarity


Electronegativity is unequal sharing of electrons.

What specifically occurs in electronegativity? The force of atoms is being pulled on its electrons.

  • Up means an increase in electronegativity, force of pulling of electrons

  • Across means the decrease in electronegativity, force of pulling electrons.

  • Fluorine, Oxygen, and Nitrogen have the most high electronegativity

  • Electronegativity leads to polarity. 


Polarity

  • Nonpolar molecules have an equal sharing of electrons.

  • Polar molecules have slight charges, an unequal share of electrons.


Ionic bonding is the taking/giving of electrons (only the strongest bond when NOT in water)

  • Produced of ions (charged ions)

  • Cations are positively charged ions

  • Anions are negatively charged ions.

Hydrogen bondings (weakest bond) are between polar covalent molecules, specifically between the slightly positive and slightly negative ions.

  • It does NOT have to be a hydrogen to be a hydrogen bond, just has to be between slightly positive and slightly negative molecules.


Van der Waals Interactions is the random movement of electrons that create a small charge in the nonpolar molecule.


PET Scan Exercise

A patient has a positive mammogram and now we need to know if the breast tumor has spread, so a PET scan has been ordered. A PET Scan uses FDG. What type of bonding holds fluorine-18 to the glucose molecules? Fluorine-18 will release a positron as it decays, this is an example of what type of decay? In this type of decay, did the atomic number change? Did the atomic mass change? Now, look at the image and determine if the cancer has spread. 


  1. What type of bonding holds fluorine-18 to the glucose molecules? Covalent bonding

  2. This is an example of what type of decay? Beta-plus decay

  3. Did the atomic number change? Yes

  4. Did the atomic mass change? No

Has the cancer spread? Yes, it’s gone into the patient's lymph nodes.