Bio 103 Exam 1 Study Guide (Chapters 1-6)

A comprehensive set of question-and-answer flashcards covering emergent properties, levels of biological organization, chemistry basics, water properties, carbon, biological molecules, and cell biology (Chapters 1-6) for Bio 103 Exam 1 preparation.

What is an emergent property in biology?

A property that arises at a higher level of organization and cannot be predicted just from the properties of its components; it results from interactions among parts.

List the levels of biological organization from molecule to ecosystem in order.

Molecule → organelle → cell → tissue → organ → organ system → organism → population → community → ecosystem → biome → biosphere.

Give an example for each level of biological organization (molecule, organelle, cell, etc.).

Molecule: H2O; Organelle: mitochondrion; Cell: neuron; Tissue: muscle tissue; Organ: heart; Organ system: circulatory system; Organism: human; Population: group of kangaroos; Community: forest with trees and fungi; Ecosystem: freshwater pond; Biome: desert; Biosphere: Earth.

How is information transmitted in biological systems?

Genetic information is passed from DNA to RNA to protein (central dogma); signaling pathways also transmit information between cells.

What are examples of transformation of materials and energy in biological systems?

Photosynthesis converts light energy to chemical energy; cellular respiration converts chemical energy to ATP; digestion transforms food into usable nutrients.

How do interactions between elements shape biology?

Interactions lead to emergent properties, feedback loops, chemical cycles, and complex system behaviors beyond individual elements’ properties.

What does descent from a common ancestor explain about unity and diversity in life?

All life shares fundamental features (e.g., genetic code, cellular organization) while diverging into many forms due to adaptation and speciation.

Name the four elements that make up >95% of human body mass.

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

Name some elements that make up the remaining ~5% of the body (examples, not percentages).

Phosphorus (P), Sulfur (S), Potassium (K), Sodium (Na), Chlorine (Cl), Magnesium (Mg), Calcium (Ca), Iron (Fe), and others.

Compare polar covalent, nonpolar covalent, ionic, and hydrogen bonds.

Nonpolar covalent: equal sharing of electrons; Polar covalent: unequal sharing (polar molecules); Ionic: transfer of electrons forming charged ions; Hydrogen bonds: attractions between partial charges in polar molecules (often involving H).

How does electronegativity relate to polar bonds and hydrogen bonding?

Differences in electronegativity create polar bonds; polar molecules have partial charges that enable hydrogen bonds between molecules. Hydrogen bonds occur specifically between polar molecules containing H bound to electronegative atoms.

Why do water molecules have polar covalent bonds?

Oxygen is more electronegative than hydrogen, leading to unequal sharing of electrons and a partial negative charge on O and partial positive charges on H.

What causes partial charges in water, and how do they lead to hydrogen bonding?

The unequal electron distribution creates partial charges; the positive H and negative O attract partial charges on neighboring molecules, forming hydrogen bonds.

Identify the four emergent properties of water essential for life and give an example of each.

1) Cohesion and adhesion (capillary action in plants); 2) High specific heat capacity (stabilizes body temperature); 3) High heat of vaporization (sweating cools by evaporation); 4) Water as a versatile solvent (NaCl dissolves in water).

What role do hydrogen bonds play in water’s emergent properties?

Hydrogen bonds enable cohesion/adhesion, contribute to high heat capacity and high heat of vaporization, and facilitate water’s solvent abilities.

Provide a simple definition of a hydrocarbon and give a simple example.

A hydrocarbon is an organic compound composed only of carbon and hydrogen. Example: methane (CH4) or ethane (C2H6).

What is ATP and why is it important in biology?

ATP (adenosine triphosphate) is the cell’s primary energy currency; energy is released when it is hydrolyzed to ADP and inorganic Pi to power cellular processes.

Describe dehydration synthesis and hydrolysis in terms of water and bonds.

Dehydration synthesis: water is removed as monomers join to form a polymer via a covalent bond; Hydrolysis: water is added to break a bond and split a polymer into monomers.

For carbohydrates, proteins, and nucleic acids, identify the monomer, polymer, and bond type; which macromolecule type does not form monomers/polymers?

Carbohydrates: monomer = monosaccharide; polymer = polysaccharide; bond = glycosidic. Proteins: monomer = amino acid; polymer = polypeptide; bond = peptide bond. Nucleic acids: monomer = nucleotide; polymer = polynucleotide; bond = phosphodiester. Lipids do not form true polymers.

What major roles does each macromolecule class play in the cell?

Carbohydrates: energy, storage, and structure; Proteins: enzymes, transport, structure, signaling; Lipids: energy storage, membranes, signaling; Nucleic acids: store and transmit genetic information; enable gene expression.

Name the three lipid types and their primary cellular roles.

Triglycerides (storage lipids); Phospholipids (membranes); Steroids (signaling molecules).

What is the basic structure of a triglyceride and how does it relate to hydrophobicity?

Glycerol backbone with three fatty acid tails; ester bonds link them; long nonpolar hydrocarbon tails make triglycerides highly hydrophobic (water-insoluble).

Which fats have one or more double bonds, and how does this affect their physical state at room temperature?

Unsaturated fats have one or more double bonds; they are typically liquid at room temperature, whereas saturated fats (no double bonds) are usually solid.

Explain how triglyceride structure relates to health impacts of fats.

Unsaturated fats (with double bonds) are generally healthier for heart health than saturated fats (no double bonds), which can raise LDL cholesterol.

Describe the basic structure of a phospholipid and how this relates to the phospholipid bilayer.

Phospholipid with a hydrophilic phosphate-containing head and two hydrophobic fatty acid tails; forms a phospholipid bilayer with the heads facing aqueous environments and tails facing inward.

What is the basic structure of a steroid and how does it relate to signaling molecules?

Steroids have four fused carbon rings (cholesterol is a lipid precursor); hydrophobic; many steroids function as hormones and signaling molecules.

Distinguish monosaccharides, disaccharides, and polysaccharides; which are polymers?

Monosaccharides are monomers; disaccharides and polysaccharides are polymers formed by glycosidic bonds.

What are some general functions of sugars/carbohydrates in the human body?

Immediate energy (glucose), energy storage (glycogen, starch), and structural/support roles (cellulose in plants, chitin in some invertebrates); components of nucleic acids (ribose, deoxyribose) and recognition molecules.

Describe the basic structure of nucleotides and nucleic acid polymers; what backbone bonds connect nucleotides?

Nucleotides consist of a sugar, a phosphate group, and a nitrogenous base; nucleotides link to form polynucleotides via phosphodiester bonds forming the backbone.

What are the three components of an amino acid, and which groups form peptide bonds?

Amino group, carboxyl group, and an R group (side chain). Peptide bonds form between the carboxyl carbon of one amino acid and the amino nitrogen of the next.

What are the three broad categories of amino acids by R group?

Nonpolar/hydrophobic, polar/hydrophilic, and charged (positively or negatively charged) hydrophilic.

Define primary, secondary, tertiary, and quaternary protein structure and the bonds involved.

Primary: amino acid sequence held by peptide bonds; Secondary: local folding (alpha-helix, beta-pleated sheet) stabilized by backbone hydrogen bonds; Tertiary: overall 3D shape stabilized by ionic, hydrogen, hydrophobic interactions, and disulfide bonds; Quaternary: assembly of multiple polypeptides, with similar bonds as in tertiary interactions.

Which structural elements are characteristic of secondary protein structure?

Alpha-helices and beta-pleated sheets, stabilized by hydrogen bonds between the backbone.

How does primary structure influence secondary and beyond?

The amino acid sequence (primary structure) dictates how the backbone hydrogen bonds can form, thus determining secondary structure and ultimately tertiary and quaternary folding.

Name several functional categories of proteins and provide an example for each.

Enzymes (amylase) – catalytic; Transport (hemoglobin) – transport of substances; Structural (collagen) – provides support; Storage (casein) – nutrient reservoir; Motor (myosin) – movement; Receptor (insulin receptor) – signaling; Defense (antibodies) – immune; Signaling (insulin) – hormonal signaling.

Differentiate prokaryotic and eukaryotic cells and give examples of organisms in each group.

Prokaryotic: bacteria and archaea; no nucleus or membrane-bound organelles. Eukaryotic: animals, plants, fungi, and protists; have a nucleus and membrane-bound organelles.

What are the four common cell components shared by all cells?

Plasma membrane, cytosol (cytoplasm), chromosome (DNA), and ribosomes.

What are the major components of the eukaryotic endomembrane system?

Rough endoplasmic reticulum, smooth endoplasmic reticulum, Golgi apparatus, lysosomes, and vesicles (and the nuclear envelope is closely related).

What is the nucleus and what is the role of nuclear pores?

The nucleus houses the cell’s genetic material; nuclear pores regulate the transport of DNA, RNA, and ribosomal subunits between the nucleus and cytoplasm.

Where does protein synthesis occur in the cell, and what are the fates of the synthesized proteins?

Protein synthesis occurs on free ribosomes in the cytosol and on ribosomes on the rough endoplasmic reticulum; fates include membrane proteins, secretory proteins, and cytosolic proteins.

What are the differences between the rough and smooth ER?

Rough ER has ribosomes and synthesizes secretory and membrane proteins; smooth ER lacks ribosomes and is involved in lipid synthesis and detoxification.

What is the Golgi apparatus, and what do cis and trans sides signify?

The Golgi modifies, sorts, and packages proteins for secretion or delivery; cis side receives from the ER, trans side ships to final destinations.

What functions do mitochondria and chloroplasts serve, and what evidence supports the endosymbiont theory?

Mitochondria produce ATP via respiration; chloroplasts perform photosynthesis. Evidence: own DNA, ribosomes similar to bacteria, double membranes, and similar replication to bacteria.

What are the major functions of the cytoskeleton, and what are centrioles?

Cytoskeleton provides cell shape, organization, and tracks for movement; centrioles act as focal points for spindle formation in animal cells during division.

What are the main types of cell junctions in plants and animals and their functions?

Plants: plasmodesmata (channels between cells for transport and communication). Animals: tight junctions (seal) prevent leakage; desmosomes (strength) provide mechanical stability; gap junctions (communication) allow small molecules to pass between cells.

How do phospholipids arrange themselves to form a cell membrane?

They form a bilayer with hydrophilic heads facing the aqueous environment inside and outside the cell, and hydrophobic tails facing each other in the interior of the membrane.

A genetic mutation causes a person’s aquaporin channels to be non-functional. Which emergent property of water is most directly impacted in terms of cellular transport?

Water as a versatile solvent and its cohesive/adhesive properties are impacted. Aquaporins facilitate rapid transport of water (solvent) across membranes, which is crucial for maintaining cellular hydration and osmotic balance, relying on water's ability to interact with and move through environments.

What is the primary function of lysosomes in a eukaryotic cell, and which macromolecules do they target for degradation?

Lysosomes are centers for cellular digestion. They contain hydrolytic enzymes that break down waste materials, cellular debris, and foreign invaders (like bacteria), targeting all major macromolecules (carbohydrates, lipids, proteins, and nucleic acids).

Which type of non-covalent bond is primarily responsible for stabilizing the alpha-helix and beta-pleated sheet structures in proteins?

Hydrogen bonds between the carbonyl oxygen of one amino acid and the amino hydrogen of another amino acid in the polypeptide backbone are primarily responsible for stabilizing secondary protein structures.

If a plant cell is placed in a solution with a much higher solute concentration than its cytoplasm, what is the most likely observed effect on the cell's central vacuole and plasma membrane?

Due to osmosis, water will move out of the cell. The central vacuole will shrink, and the plasma membrane will pull away from the cell wall, a process called plasmolysis.

What is the key difference in carbohydrate structure between starch (energy storage in plants) and cellulose (structural component of plant cell walls)?

Starch is composed of alpha-glucose monomers, allowing for helical and easily hydrolyzed chains. Cellulose is composed of beta-glucose monomers, which form straight, rigid chains stabilized by hydrogen bonds, making it difficult to digest for most organisms.