Biology and Chemistry of Life Review

Flashcards covering Chapter 1 (Biology), Chapter 2 (Molecules and Water), and Chapter 3 (Chemical Building Blocks of Life) based on lecture notes.

What is the definition of Biology?

The study of life.

What are the seven characteristics of life

Cellular organization, Ordered complexity, Sensitivity, Growth, development, and reproduction, Energy utilization, Homeostasis, and Evolutionary adaptation.

What are the four hierarchical levels of life mentioned in the notes?

Chemical level, Cellular level, Tissue level, and Organismal level.

What is an emergent property?

Property that appears when components interact to form a more complex system

In scientific investigation, what is the difference between deductive and inductive reasoning?

Deductive reasoning applies general principles to predict specific results, while Inductive reasoning uses specific observations to construct general scientific principles.

What is a hypothesis?

A suggested explanation that can be tested through experimentation.

In an experiment, what is the purpose of a control group?

A group where the variable being tested is not changed, used for comparison.

What is a scientific theory?

A body of interconnected concepts supported by much experimental evidence and scientific reasoning.

What is the difference between artificial selection and natural selection?

Artificial selection involves human-driven breeding for specific traits, whereas Natural selection is the process where environmental factors drive differential survival and reproduction.

What is the difference between homologous and analogous structures?

Homologous structures have the same evolutionary origin but may differ in structure and function; analogous structures have similar functions but different evolutionary origins.

What is the mass, location, and charge of a Proton?

Mass: $1\,amu$, Location: nucleus, Charge: positive ($+1$).

What is the mass, location, and charge of a Neutron?

Mass: $1\,amu$, Location: nucleus, Charge: neutral ($0$).

What is the mass, location, and charge of an Electron?

Mass: negligible, Location: orbitals/shells surrounding nucleus, Charge: negative ($-1$).

How is the atomic number of an atom determined?

By the number of protons in the nucleus.

How is the atomic mass of an atom calculated?

By the sum of the number of protons and neutrons.

What is the difference between a cation and an anion?

A cation is a positively charged ion; an anion is a negatively charged ion.

What is an isotope?

Atoms of a single element that possess different numbers of neutrons.

What are valence electrons and the rule of octet?

Valence electrons are electrons in the outer shell; atoms lose, gain, or share electrons to fill their outer shell with 8 electrons (Rule of Octet).

Define Oxidation and Reduction in terms of electron transfer.

Oxidation is the loss of electrons; Reduction is the gain of electrons.

Which four elements make up more than $95\%$ of biological matter?

Carbon ($C$), Hydrogen ($H$), Oxygen ($O$), and Nitrogen ($N$).

Name the 12 most abundant elements in life mentioned in the notes.

$C, H, O, N, Na, K, Cl, Ca, P, S, Fe, Mg$.

What is the difference between a molecule and a compound?

A molecule is a group of atoms held together by chemical bonds; a compound is a molecule containing more than one element.

What is an ionic bond?

A bond formed by the attraction between oppositely charged ions (cations and anions) resulting from REDOX reactions.

What is a covalent bond?

A bond formed when atoms share one or more pairs of valence electrons.

What is electronegativity?

An atom's affinity for electrons; it determines how electrons are shared in a covalent bond.

Distinguish between polar covalent bonds and non-polar covalent bonds.

Polar covalent bonds involve unequal sharing of electrons due to differences in electronegativity (e.g., $O-H$, $N-H$); non-polar covalent bonds involve equal sharing (e.g., $C-C$, $C-H$).

What happens to atoms during a chemical reaction?

Atoms are not created or destroyed, but chemical bonds are broken and formed.

Identify factors that affect the rate of a chemical reaction.

Temperature, concentration of reactants and products, and catalysts.

Define Cohesion and Adhesion in relation to water.

Cohesion: water molecules sticking to other water molecules; Adhesion: water molecules sticking to other polar surfaces.

What are five properties of water that benefit life?

Cohesion, Adhesion, High specific heat, High heat of vaporization, Lower density of ice, and the ability to dissolve many substances.

What is the difference between hydrophobic and hydrophilic substances?

Hydrophilic substances are water-loving (polar); hydrophobic substances are water-fearing (non-polar).

How do Acids and Bases affect the concentration of $H^+$ and pH?

Acids increase $H^+$ concentration and lower pH ($<7$); Bases decrease $H^+$ concentration and raise pH ($>7$).

What is a buffer?

A substance that resists changes in pH by reacting with free $H^+$ when acids are added and releasing $H^+$ when bases are added.

What defines a hydrocarbon?

Molecules consisting only of Carbon and Hydrogen; they are non-polar and hydrophobic.

What are functional groups in organic chemistry?

Specific groups of atoms attached to carbon skeletons that provide distinct chemical properties (e.g., Hydroxyl, Carboxyl, Amino).

Define Isomer and name two types.

Molecules with the same molecular formula but different structures; types include structural isomers and stereoisomers.

What is the difference between dehydration synthesis and hydrolysis?

Dehydration synthesis links monomers to form polymers by removing water; Hydrolysis breaks polymers into monomers by adding water.

What is the general chemical formula for a carbohydrate?

$C_nH_{2n}O_n$ where $n$ is the number of carbons.

Identify three main 6-carbon monosaccharides.

Glucose, Fructose, and Galactose.

Name three major disaccharides.

Sucrose, Maltose, and Lactose.

List four major polysaccharides and their general functions.

Starch (energy storage in plants), Glycogen (energy storage in animals), Cellulose (structural support in plant cell walls), Chitin (structural support in fungi and arthropod exoskeletons).

What are the two main types of nucleic acids and their monomers?

DNA and RNA; their monomer is the Nucleotide.

What are the three parts of a nucleotide?

A Phosphate group, a $5C$ sugar (ribose or deoxyribose), and a nitrogenous base.

Distinguish between Purines and Pyrimidines.

Purines: adenine ($A$) and guanine ($G$); Pyrimidines: cytosine ($C$), thymine ($T$ - DNA only), and uracil ($U$ - RNA only).

What are the nucleic acid base pairing rules?

Adenine pairs with Thymine ($A-T$) or Uracil ($A-U$); Guanine pairs with Cytosine ($G-C$).

List four differences between DNA and RNA.

1. DNA is double-stranded; RNA is single-stranded. 2. DNA stores genetic info; RNA sends genetic info. 3. DNA has deoxyribose; RNA has ribose. 4. DNA has $T$; RNA has $U$.

What is the monomer of a protein, and how many types lead to protein diversity?

Amino acids are the monomers; 20 different amino acids are used.

What are the five parts of an amino acid?

Amino group, Carboxyl group, Central carbon, Hydrogen, and a Variable R group.

What bond connects amino acids in a polypeptide?

Peptide bonds.

Define the four levels of protein structure.

Primary (sequence of amino acids), Secondary (alpha helices and beta sheets), Tertiary (final 3D shape), Quaternary (interaction between multiple polypeptide chains).

What is protein denaturation and what factors cause it?

Unfolding of a protein rendering it non-functional; caused by changes in Temperature, pH, or Ionic concentration.

What characterizes a lipid?

Hydrophobic biomolecules that are insoluble in water.

Describe the structure and function of a triglyceride.

Structure: 3 fatty acids linked to a glycerol; Function: energy storage.

What is the difference between saturated and unsaturated fatty acids?

Saturated: maximum hydrogens, animal origin, solids at room temp, higher energy. Unsaturated: fewer than max hydrogens, plant origin, liquids at room temp, lower energy.

What is the structure and function of a phospholipid?

Structure: Glycerol, Two fatty acids, and a Phosphate group; Function: Form phospholipid bilayers, the basis for biological membranes.