CHAPTER 1-3 BIO 121 LECTURE NOTES FOR QUIZ, Lecture notes of Molecular biology

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Biology

Biology Lecture Notes

Level 1 : What are the essential

characteristics of living things?

Living things are

organized!

They react to diverse

stimuli!

All living things use

an energy source

for their metabolic

functions

What are atoms?

• An Atom is the smallest unit of matter composed of protons, neutrons and electrons that forms a chemical element
• Two or more securely bonded atoms forms a molecule

What are cells?

• Cells are the basic building blocks of life! Cells are the structural and functional units of all living things and are made up of molecules.

Examples Of Different Organ Systems: Organ system

Cardiovascular Transports oxygen, nutrients, and

other substances to the cells and

transports wastes, carbon dioxide,

and other substances away from the

cells; it can also help stabilize body

temperature and pH

Heart, blood, and blood vessels

Digestive Processes foods and absorbs

nutrients, minerals, vitamins, and

water

Mouth, salivary glands, esophagus,

stomach, liver, gallbladder, exocrine

pancreas, small intestine, and large

intestine

Function Organs, Tissues and Structures Involved

Links for more info:

Video explanations and reference links:

Introduction to atoms - Introduction to the atom (video) | Khan Academy

What is a molecule? - https://www.youtube.com/watch?time_continue=48&v=C0Qaf-

UJ2XQ&embeds_referring_euri=https%3A%2F%2Fwww.bing.com%2F&embeds_referring_origin=https%3A%2F%2F

www.bing.com&source_ve_path=Mjg2NjQsMjg2NjY&feature=emb_logo

Tissues, organs and organ systems - Tissues, organs, & organ systems (article) | Khan Academy

Elements Of Life (CHNOPS) All living and nonliving things are matter composed of elements. There are six basic elements that make up 99% of the biomolecules which are found in living organisms. (Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorous, Sulfur)

• This means 99% of your body , a tree, a mushroom and even bacteria are made up of (CHNOPS)

Atomic Structure:

The atomic structure refers to the

structure of an atom comprising a

nucleus (center) in which the protons

(positively charged) and neutrons

(neutral) are present. The negatively

charged particles called electrons

revolve around the centre of the

nucleus.

Electrons

• The atomic weight of an electron is 0
• Electrons are located in the shell

around the nucleus.

• The first ring (shell) closest to the

nucleus only holds Max. of 2 electrons.

The second ring (shell) holds max. Of 8

electrons. The third Ring (Shell) can

hold up to 18. But for this example,

Sodium’s third ring (shell) will only

have 1 electron.

Ions: Losing & Gaining Electrons

Elements gain stability by completing their octet, or having eight electrons in their valence (outer) shell. Elements lose or gain

electrons to attain an electron configuration of the nearest noble gas. Noble gases have a completely filled valence shell, which

makes them stable.

There are two type of ions… Positively charged ions called Cations

Cations are positively charged ions and are

formed when an atom loses one or more

electrons.

Metals will lose electrons to become a

positive cation (ex. Sodium)

Negatively charged ions are called Anions

Anions are negatively charged ions created

when an atom gains one or more electrons.

nonmetals (ex. Gases) will gain electrons to

become a negative anion. (Chlorine)

Ionic Bonding Covalent Bonding Hydrogen Bonding Ionic bonding is the complete transfer of valence electron(s) between atoms and is a type chemical bond that generates two oppositely charged ions. Covalent bonding is a chemical bond that involves the sharing of electrons to form electron pair between atoms. Polar covalent bonding involves the unequal sharing of electrons. Nonpolar covalent bonding involves an equal sharing of electrons. A hydrogen bond is an intermolecular force (IMF) that forms a special type of dipole-dipole attraction when a hydrogen atom bonded to a strongly electronegative atom exists in the vicinity of another electronegative atom with a lone pair of electrons. Dipole-dipole forces, also known as dipole-dipole interactions, are the electrostatic forces between two permanent polar molecules.

Examples: ionic Bonding Ionic bonding is a type of chemical bonding that involves the transfer of electrons from one atom to another.Here are some examples of ionic bonding: ● Sodium Chloride (NaCl): Sodium chloride is an ionic compound that forms when sodium (Na) donates an electron to chlorine (Cl). ● Calcium Chloride (CaCl 2 ): Calcium chloride is an ionic compound that forms when calcium (Ca) donates two electrons to chlorine (Cl). Covalent Bonding

Covalent bonding is a type of

chemical bonding where atoms share

electrons. Examples of covalent

bonding include:

1. Water (H 2 O), where hydrogen

and oxygen share electrons.

2. Molecular oxygen (O 2 ), where

oxygen atoms share electrons.

3. Ammonia (NH 3 ), where nitrogen

and hydrogen share electrons.

Hydrogen Bonding

Hydrogen bonds are weak

interactions between a hydrogen

atom and an electronegative atom,

such as oxygen, nitrogen, or fluorine.

Here are some examples of hydrogen

bonds:

● Water molecules joining

together

Links for more info:

Video explanations and reference links:

The Ph Scale https://chem.libretexts.org/Bookshelves/Physical_and_Theoretical_Chemistry_Textbook_Maps/Supplemental_Modules_(Physical_and_T heoretical_Chemistry)/Acids_and_B ases/Acids_and_Bases_in_Aqueous_Solutions/The_pH_Scale Acid vs Base https://bio.libretexts.org/Courses/Minnesota_State_Community_and_Technical_College/Biology_of_Human_Concerns_(Daniels)/ 02 % 3 A_Chemistry_of_Life/2.12% 3 A_Acids_ and_Bases#:~:text=If% 20 a% 20 solution% 20 has% 20 a% 20 lower% 20 concentration% 20 of,strong% 20 bases% 20 can% 20 harm% 20 organisms% 20 and% 20 damage% 20 materials. Covalent Bonds https://www.khanacademy.org/science/ap-biology/chemistry-of-life/introduction-to-biological-macromolecules/v/covalent-bonds Ionic Bonds https://www.khanacademy.org/science/ap-biology/chemistry-of-life/introduction-to-biological-macromolecules/v/ionic-bonds Hydrogen bonding https://youtu.be/ltxqQbiI 6 - o Ph Scale video explanation: https://youtu.be/ckbsHM 2 igT 0 Isotopes & Mass spectrometry https://www.khanacademy.org/science/ap-chemistry-beta/x 2 eef 969 c 74 e 0 d 802 :atomic-structure-and-properties/x 2 eef 969 c 74 e 0 d 802 :mass- spectrometry-of-elements/a/isotopes-and-mass-spectrometry Ion: Losing & gaining electrons w/ video explanation https://scienceoxygen.com/how-do-you-determine-if-an-element-will-lose-or-gain-electrons/

Level 3 : Organic Compounds