Bio 160 Fall 2023: Exam 1

5 Characteristics of Life

5 Characteristics of Life

1. Consists of 1 or more cells

2. Processes Information

3. Capable of replication/reproduction

4. Processes Energy

5. Is a Product of Evolution

Cell Theory

All organisms are made of cells and all cells come from pre-existing cells

5 Core Concepts of Biology

1. Evolution

2. Structure and Function

3. Information Flow, Exchange, and Storage

4. Pathways & Transformation of Energy & Matter

5. Systems

Valence Electrons

number of electrons in an atom’s outer shell

Ionic Bond

a metal and non-metal lose and gain electrons respectively to become more stable, which creates electrically attracted ions

Covalent Bond

2 non-metals share electrons to achieve stability

Polar Covalent Bonds

2 non-metals with unequal electronegativities

Non-polar Covalent Bonds

2 non-metals with equal electronegativities

Hydrogen Bonding

specific kind of intermolecular force where Hydrogen bonds to Nitrogen, Oxygen, and Fluorine

Solvent

liquid that other substances are dissolved in (Ex: Water in a glass of salt water)

Hydrophilic

Water loving, will dissolve and interact with water

Hydrophobic

Water fearing, will not dissolve or interact with water

Cohesion

Molecules stick to one another

Adhesion

molecules stick to polar or charged surfaces

What allows water to resist changes in temperature?

Polarity and Hydrogen Bonding

In a glass of pure water, list 2 different kinds of bonds occurring and indicate strongest & weakest.

Polar Covalent (Strongest) and Hydrogen Bonds (Weakest)

Why does ice float?

Liquid water is denser than solid water (ice) due to hydrogen bonding

What makes something an Organic Molecule?

Contains at least 1 C-H Bond

What does pH stand for?

Potential Hydrogen

Acids are found ______________ on the pH scale because they have a ___________ concentration of Hydrogen (H+) ions

from 1-6.999, higher

Bases are found ______________ on the pH scale because they have a ___________ concentration of Hydrogen (H+) ions

from 7.001-14, lower

What substance has a pH of 7?

Pure Water

How many bonds can carbon form?

4

What Functional Group is this?

Amino Group

What Functional Group is this?

Carbonyl Group

What Functional Group is this?

Carboxyl Group

What Functional Group is this?

Hydroxyl Group

What Functional Group is this?

Phosphate Group

What Functional Group is this?

Sulfhydryl Group

Condensation Reactions ___________ a bond and ___________ a molecule of water

form, release

Hydrolysis Reactions ___________ a bond and ___________ a molecule of water

break, use/require

Which functional groups act as acids?

Carboxyl, Hydroxyl

Which functional group acts as a base?

Amino

Sulfhydryl Functionals groups can link together via _____________ bonds

Disulfide bonds

Name some of the functions of Proteins

structure, energy storage, movement, transport, catalysis, defense, and signaling

What kind of protien catalyzes reactions?

Enzymes (they usually end in “-ase”

Define Amino Acid.

monomer of proteins

What part of the Amino Acid determines identity?

The side-chain

If the R group has a negative charge, it’s __________

acidic

If the r group has a positive charge, it’s ____________

basic

If the r group contains Oxygen it’s _________

polar

If the r group isn’t charged and doesn’t contain Oxygen, it’s probably

Non-polar

What kind of bond links Amino Acids

Peptide Bond

Is a peptide bond a hydrolysis or condensation reaction?

Condensation

Protein’s Primary Structure

Peptide Chain

Protein’s Secondary Structure

α-helix or β-pleated sheets

Protein’s Tertiary Structure occurs when the α-helix or β-pleated sheets begin to fold in on themselves. What causes this?

Hydrogen bonds, hydrophobic interactions, Van Der Waals forces, and disulfide bonds

What is protein’s quaternary structure?

Multiple proteins linked together and functioning as a unit

Proteins must be ____________ correctly or they cannot function

folded

What do Prions do?

cause protiens to misfold in brain cells, leading to death

What is a nucleotide?

monomer of nucleic acids

What are the 3 parts of a nucleotide?

5-carbon sugar, phosphate group, nitrogenous base

Which part of a nucleotide determines identity?

Nitrogenous base

How do we number the carbons on our 5-carbon sugar?

starting with the carbon linked to the nitrogenous base and moving clockwise

List the 5 Nitrogenous bases

Adenine, Thymine, Guanine, Cuytosine, and Uracil

Which nitrogenous base is ONLY found in RNA?

Uracil

Which nitrogenous base is ONLY found in DNA?

Thymine

Adenine pairs with_____ and ________

thymine and uracil

Guanine Pairs with

Cytosine

Purines (double ring)

Adenine and Guanine

Pyrimidines (single ring)

Thymine, Uracil, and Cytosine

What is the bond that links 2 nucleotides?

Phosphodiester Linkage

How does a Phosphodiester Linkage form?

The 3’ carbon on the 5-carbon sugar links to the phosphate group of the nucleotide being added.

The 5’ end always has an exposed ______________ group

Phosphate

The 5’ end always has an exposed ______________

3’ carbon

New nucleotides are always added to the 3’ end of the strand

Primary Structure of Nucleic Acids

Polynucleotide

2 DNA strands together form a ______________, the secondary structure of nucleic acids

Double Helix

Complementary DNA strands run __________

Anti-parallel

In RNA, a single strand doubles back on itself to form a ___________

hairpin

What bond forms between 2 nitrogenous bases?

hydrogen bonds

Is a phosphodiester linkage a condensation or hydrolysis reaction?

Condensation

Polar molecules are hydro_________

philic

Non-polar molecules are hydro_________

phobic

Carbohydrates contain what elements?

C, O, and H

What is the monomer of a carbohydrate?

Monosachharides

Most Carbohydrates end in ________

-ose

How many carbons do typical carbohydrates have?

Minimum 3, Rarely more than 6

Carbohydrates can be _________ or _____________

linear, ring structure

If a carbonyl group is in the middle of the carbon chain, then it’s an _______

aldose

If a carbonyl group is at the end of the carbon chain, then it’s a _______

ketose

How are monosaccharides bonded together?

Glycosidic Linkages

If the 2 carbons involved in bonding have the same stereochemistry, it’s an __________

α-1,4 Glycosidic Linkage

If the 2 carbons involved in bonding have different stereochemistry, it’s a ____________________

β-1,4 Glycosidic Linkage

Glycosidic linkages always occur between which carbons?

1 and 4

What other macromolecule contains a monosaccharide?

Nucleotide

Which polysaccharides store chemical energy?

Starch and Glycogen

Which polysaccharides are present in cell walls?

Cellulose, Chitin, and Peptidoglycan

Starch’s monosaccharide is __ glucose

α

Glycogen’s monosaccharide is __ glucose

α

Cellulose’s monomer is ___________

β-glucose

Chitin’s monomer is _______

NAG

Peptidoglycan’s monomers are _______ & __________

NAG and NAM

Does Glycogen form arrays or helices

Helices

Does Starch form arrays or helices

Helices

Does Celluose form arrays or helices

arrays

Does Chitin form arrays or helices

arrays

Does Peptidoglycan form arrays or helices

arrays

Parallel strands in Cellulose are joined by______________

hydrogen bonds

Parallel strands in Chitin are joined by______________

Hyrdogen bonds