Intro to Biology - Flashcards 3

Flashcards covering core concepts from the biology lecture notes, including cell theory, molecular biology, bioenergetics, evolution, and organelle structure/function.

What is biology?

The scientific study of life.

What are the seven characteristics of life that distinguish living organisms from non-living matter?

Order, reproduction, growth and development, energy processing, regulation, response to the environment, and evolutionary adaptation.

What is the difference between prokaryotic and eukaryotic cells?

Prokaryotic cells are smaller and lack a membrane-bound nucleus and organelles (DNA in a nucleoid). Eukaryotic cells are larger and have a membrane-bound nucleus and organelles.

What does homeostasis mean?

Maintenance of a stable internal environment in the face of external changes.

What is adaptive evolution and provide an example?

Beneficial heritable traits increase in a population through natural selection; e.g., camouflage improving survival.

What is metabolism?

All chemical reactions in the body that sustain life.

List the biological organization levels from molecules to the biosphere.

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

What are emergent properties?

New properties that arise at higher levels of organization that are not present in the component parts.

What is taxonomy and what are the three domains of life?

Taxonomy is the science of classifying, describing, and naming organisms. The three domains are Bacteria, Archaea, and Eukarya.

What is the Central Dogma of biology?

DNA stores information and is transcribed into RNA, which is translated into proteins.

What are the two core themes of biology regarding energy and matter in ecosystems?

Life depends on the flow of energy (sun→producers→consumers) and the transformation of energy and the cycling of matter.

What are the steps of the scientific method as described in the notes?

Observe → Question → Hypothesize → Test → Analyze → Conclude → Share.

How are structure and function related in biology?

They are interdependent; the shape or structure of a molecule or organ usually influences its function (e.g., hemoglobin’s shape enables oxygen transport).

Name two key properties of water that arise from hydrogen bonding.

Water is polar and a good solvent; it has high cohesion/adhesion and high heat capacity/vaporization, and ice is less dense than liquid water.

What is pH and how do acids and bases relate to it?

pH is the negative log of hydrogen ion concentration; 0–14 scale; acids increase [H+], bases decrease; buffers stabilize pH.

What is the hydroxyl functional group and where is it commonly found?

-OH; polar group found in alcohols and many biomolecules; increases solubility.

What is the carbonyl group and what are the two main types?

C=O group; ketone and aldehyde; carbonyl carbon double-bonded to oxygen.

What is the carboxyl group and its role in biology?

-COOH; carboxylic acids; acidic properties; ionizes to -COO−.

What is the amino group in amino acids?

-NH2; amino group; becomes -NH3+ in certain conditions; fundamental in amino acids.

What is the phosphate group and where is it found in biology?

-OPO3^2−; found in nucleotides and ATP; contributes to energy transfer and nucleic acid backbone.

What is the sulfhydryl group and its significance?

-SH; thiols; can form disulfide bonds that stabilize protein structure.

What is the methyl group and why is it important?

-CH3; nonpolar; affects molecule properties and function, often in signaling or gene expression.

What is the difference between ions and isotopes?

Ions are atoms with a net electric charge (extra or missing electrons). Isotopes are variants of the same element with different numbers of neutrons.

What is a monomer and what is a polymer?

Monomer is a building block; polymers are long chains formed by linking monomers.

What is dehydration synthesis and hydrolysis?

Dehydration synthesis links monomers by removing water (builds polymers); hydrolysis breaks polymers by adding water (releases energy in catabolic steps).

What are the four major macromolecules?

Carbohydrates, proteins, nucleic acids, and lipids (lipids are not true polymers).

What are the four levels of protein structure?

Primary (amino acid sequence), secondary (alpha helices and beta sheets), tertiary (3D shape due to R-group interactions), quaternary (assembly of multiple polypeptides).

What is a peptide bond?

A bond formed between the carboxyl group of one amino acid and the amino group of the next amino acid via dehydration synthesis.

What is the general structure of an amino acid?

A central carbon bonded to an amino group, a carboxyl group, a hydrogen, and a variable R group.

Name some major functions of proteins.

Enzymes, transport, defense (antibodies), signaling, receptors, structural support, storage, regulatory roles.

What is the monomer for nucleic acids?

Nucleotide, composed of a sugar (ribose or deoxyribose), a phosphate group, and a nitrogenous base.

What are the differences between DNA and RNA?

DNA has deoxyribose and thymine; typically double-stranded and stores genetic information. RNA has ribose and uracil; usually single-stranded and functions in protein synthesis.

What are the base pairing rules for DNA and RNA?

In DNA, A pairs with T and C with G. In RNA, A pairs with U (and C with G).

What is the structure of DNA?

Two antiparallel polynucleotide strands form a double helix stabilized by hydrogen bonds between base pairs (A-T, C-G).

What is the endosymbiotic theory?

Mitochondria and chloroplasts originated as free-living bacteria that were engulfed by early eukaryotic cells, later evolving into organelles.

What are the three components of the cytoskeleton and their general functions?

Microfilaments (actin) support cell shape and enable movement; intermediate filaments provide mechanical strength; microtubules act as tracks for movement and organize the cell, including chromosome separation.

What are the three main types of cell junctions in animal tissues?

Tight junctions seal cells into leakproof sheets; desmosomes anchor cells into strong tissues; gap junctions create cytoplasmic channels between neighboring cells.

What are plant cell walls and plasmodesmata?

Plant cell walls are cellulose-based structures providing rigidity; plasmodesmata are channels through cell walls that connect plant cells and allow transport and communication.

What is the endomembrane system?

A network including the nucleus, ER, Golgi, lysosomes, vacuoles, and plasma membrane that coordinates synthesis, modification, packaging, and transport of cellular products.

What evidence supports the endosymbiotic origin of mitochondria and chloroplasts?

They contain their own circular DNA and ribosomes, reproduce like bacteria, and have multiple membranes (including a double membrane).