BIOL 1306 unit 1 test study guide

study guide

What is biology?

The study of living organisms and their interactions with one another and their environments.

How does biology relate to global challenges?

Biology provides insights into issues like disease outbreaks, environmental protection, and climate change.

What is the scientific method?

A structured approach to acquiring knowledge through observation, hypothesis formation, prediction, and experimentation.

What is inductive reasoning?

A method that moves from specific observations to general conclusions, forming broader scientific theories.

What is deductive reasoning?

A method that starts with general principles to predict specific outcomes, essential for testing hypotheses.

What is cell theory?

The theory stating that all living things are composed of one or more cells, and new cells arise from existing cells.

What distinguishes prokaryotic cells from eukaryotic cells?

Prokaryotic cells lack a membrane-bound nucleus, while eukaryotic cells have a nucleus and membrane-bound organelles.

Who were some pioneers of cell theory?

Hooke, van Leeuwenhoek, Schleiden, Schwann, and Virchow.

What are the core components of prokaryotic cells?

Plasma membrane, cytoplasm, ribosomes, and DNA localized in a nucleoid region.

What is the function of fimbriae in prokaryotic cells?

Fimbriae enable prokaryotic cells to attach to host surfaces, crucial for colonization.

What role do pili play in prokaryotic cells?

Pili facilitate genetic exchange during conjugation, enhancing genetic diversity.

What is the function of flagella in prokaryotic cells?

Flagella enable locomotion, allowing cells to navigate and respond to environmental stimuli.

What organelles are found in eukaryotic cells?

Mitochondria, chloroplasts, endoplasmic reticulum, Golgi apparatus, and lysosomes.

What is the role of mitochondria?

Mitochondria generate ATP through cellular respiration.

What is the function of chloroplasts?

Chloroplasts conduct photosynthesis in plants.

What are the functions of the rough and smooth endoplasmic reticulum?

The rough ER modifies proteins and synthesizes phospholipids; the smooth ER synthesizes lipids and detoxifies substances.

What is the role of the Golgi apparatus?

The Golgi apparatus sorts, tags, and packages proteins and lipids for transport.

What do lysosomes do?

Lysosomes digest macromolecules and pathogens, vital for waste management.

What is the structure of the plasma membrane?

A phospholipid bilayer with embedded proteins that regulates the passage of substances.

What is the role of microvilli?

Microvilli increase surface area for absorption, crucial for nutrient uptake.

What are intercellular junctions?

Structures that facilitate communication and maintain tissue integrity, including gap junctions, desmosomes, and tight junctions.

What is the extracellular matrix?

A structure composed mainly of collagen and proteoglycans that provides support and mediates cellular interactions.

What is the cytoskeleton?

A network of protein fibers that maintains cell shape and enables movement.

What are microfilaments and their role?

Microfilaments, composed of actin, support movements like muscle contraction and shape changes.

What is the function of intermediate filaments?

Intermediate filaments provide structural support and anchor organelles.

What do microtubules do?

Microtubules serve as tracks for vesicle transport and are vital for cell division.

What is the structure of cilia and flagella?

Cilia and flagella have a 9 + 2 microtubule arrangement that facilitates movement.

What are the six key elements that form the chemical foundation of life?

Carbon, hydrogen, nitrogen, oxygen, sulfur, and phosphorus.

What types of bonds do atoms form to create biological molecules?

Covalent, ionic, and hydrogen bonds.

What characterizes covalent bonds?

They involve shared electrons between atoms, creating strong and stable connections.

How are ionic bonds formed?

Through electron transfer, resulting in charged ions.

What is the role of hydrogen bonds in biological systems?

They are weaker attractions critical for water's properties and biomolecular structures.

Why is water considered a universal solvent?

It can dissolve polar and ionic substances, facilitating biochemical reactions.

What thermal properties of water support temperature regulation in organisms?

High specific heat capacity and heat of vaporization.

What causes the density anomaly of ice?

Hydrogen bonding forms a crystalline lattice that allows ice to float.

How do cohesion and adhesion contribute to plant water transport?

They create surface tension and enable capillary action, allowing water movement against gravity.

What are the four main types of biological macromolecules?

Carbohydrates, lipids, proteins, and nucleic acids.

What functions do carbohydrates serve in living organisms?

They act as energy sources and structural components.

What roles do lipids play in biological systems?

They store energy and form membranes.

What is the significance of nucleic acids?

They store and transmit genetic information.

What are the four structural levels of proteins?

Primary, secondary, tertiary, and quaternary.

Why is proper protein folding essential?

It is crucial for biological activity and function.

What can cause protein denaturation?

Temperature, pH changes, or chemicals.

What is the structure of DNA?

A double helix with a sugar-phosphate backbone and complementary base pairing (A-T, G-C).

What distinguishes RNA from DNA?

RNA is typically single-stranded, contains ribose sugar, and uses uracil instead of thymine.

What is the role of messenger RNA (mRNA)?

It is responsible for coding proteins by translating genetic information.

What functions do ribosomal RNA (rRNA) and transfer RNA (tRNA) serve?

rRNA contributes to ribosome structure and catalysis, while tRNA delivers amino acids during protein synthesis.

What is metabolism?

The sum of all chemical reactions within living cells that sustain life.

What are catabolic and anabolic pathways in metabolism?

Catabolic pathways break down molecules to release energy, while anabolic pathways build complex molecules requiring energy.

What is ATP and its role in cellular processes?

ATP is the primary energy currency of cells, fueling various activities like muscle contraction and active transport.

How is ATP replenished in cells?

Through catabolic pathways like cellular respiration.

What does bioenergetics study?

The flow and transformation of energy in living organisms.

What are core metabolic pathways?

They reflect the shared biochemical processes among diverse life forms, indicating a common ancestor.

What key processes emerged for energy harvesting in living organisms?

Photosynthesis and cellular respiration.

What type of metabolism did early life forms use before oxygen was abundant?

Anaerobic metabolism

What do sugars like glucose store within their bonds?

Significant chemical energy

What is the primary energy currency of cells?

ATP (Adenosine Triphosphate)

What process do photosynthetic organisms use to convert sunlight into chemical energy?

Photosynthesis

What are the products of light-dependent reactions used for in photosynthesis?

To synthesize glucose

How does energy flow through ecosystems?

Beginning with solar energy capture by plants via photosynthesis

What is the role of herbivores in the energy transfer process?

They consume plants, transferring energy to the next level of the food chain.

What does the first law of thermodynamics state?

Energy cannot be created or destroyed, only transformed or transferred.

What does the second law of thermodynamics state?

Every energy transfer increases entropy, or disorder, in the universe.

How do living systems maintain order against the trend toward disorder?

By constantly inputting energy.

What is ATP composed of?

An adenosine molecule bound to three phosphate groups.

What happens during the hydrolysis of ATP?

It releases significant free energy, which cells harness to power endergonic reactions.

How is ATP regenerated in cells?

Primarily through catabolic pathways like cellular respiration.

What is the mechanism by which energy coupling occurs?

Via phosphorylation, raising the energy state of target molecules.

What role do enzymes play in biochemical reactions?

They act as catalysts that accelerate reactions by lowering activation energy barriers.

What is the induced fit model in enzyme activity?

It describes how substrates bind to an enzyme's active site, inducing conformational changes for optimal catalysis.

What factors can affect enzyme activity?

Temperature, pH, competitive inhibitors, and noncompetitive inhibitors.

What is feedback inhibition in metabolic pathways?

When the end product of a pathway inhibits an upstream enzyme, preventing overproduction.

How do pharmaceuticals often interact with enzymes?

Many act as enzyme inhibitors to modulate metabolic pathways.

What is the significance of understanding enzyme regulation in drug development?

It allows for precise control of metabolic pathways to achieve therapeutic outcomes.

What is the role of coenzymes and cofactors in enzymatic reactions?

They assist enzymatic reactions by stabilizing enzyme structure or participating directly in catalysis.

What is the impact of temperature on enzyme activity?

Increases generally raise reaction rates but can denature enzymes if too high.

What is the importance of maintaining an optimal pH for enzyme function?

It preserves enzyme activity and substrate interaction.

What is enzyme compartmentalization, and why is it important?

It enhances reaction efficiency by preventing unwanted interactions and enabling precise metabolic regulation.

What is the role of allosteric activators in enzyme activity?

They bind to distinct sites to enhance substrate binding and catalytic activity.

What is energy transformation in biological systems?

It involves the conversion between potential energy stored in molecular bonds and kinetic energy of motion.

What is the role of enzymes in biochemical reactions?

Enzymes catalyze reactions by lowering activation energy, making processes more efficient.

What serves as the primary energy currency in cells?

ATP (adenosine triphosphate) couples exergonic and endergonic reactions through high-energy phosphoanhydride bonds.

What are the two forms of energy relevant to biological processes?

Potential and kinetic forms, with chemical energy stored in molecular bonds.

What encompasses all chemical reactions in cells?

Metabolism, which includes energy-releasing catabolic and energy-requiring anabolic pathways.

Which elements are essential for the formation of biomolecules?

Carbon, hydrogen, nitrogen, oxygen, sulfur, and phosphorus.

What are the four main types of biomolecules?

Nucleic acids, proteins, carbohydrates, and lipids.

How do covalent bonds contribute to molecular diversity?

Covalent bonds involve sharing electron pairs, allowing carbon to form four bonds and create diverse structures.

What are ionic bonds and their significance in biology?

Ionic bonds form through electron transfer, creating charged ions that stabilize many biological compounds.

What is the importance of hydrogen bonds in biological molecules?

Hydrogen bonds are critical for the properties of water and the structure of biomolecules like proteins and DNA.

What role does water play in biological systems?

Water acts as a universal solvent, facilitates biochemical reactions, and has unique properties like cohesion and adhesion.

What are the primary functions of carbohydrates?

Carbohydrates provide energy and structural support, with examples including glucose, starch, and cellulose.

What are the functions of lipids in biological systems?

Lipids store energy, form membranes, and act as signaling molecules.

What roles do proteins serve in cells?

Proteins perform enzymatic, structural, transport, and defense functions.

What is the structure of amino acids?

Amino acids consist of a central carbon bonded to an amino group, carboxyl group, hydrogen, and a variable R group.

What defines the primary structure of a protein?

The primary structure is the linear sequence of amino acids in a protein.

What stabilizes secondary structures in proteins?

Hydrogen bonds stabilize secondary structures like α-helices and β-pleated sheets.