BIOL 1308 Chapters 1 and 2: The Scientific Study of Life and The Chemistry of Life

Flashcards testing core concepts, definitions, taxonomy, formulas, and biological chemistry from Chapters 1 and 2.

What is the definition of biology based on its word roots in the study guide?

Biology is the scientific study of life, derived from bio- (meaning life) and -logy (meaning the scientific study of a subject).

What is the basic, functional unit of organization of life?

The Cell, which can exist as Unicellular (made of one cell) or Multicellular (made of two or more cells).

What are the 12 levels of biological organization listed from smallest to largest?

Atom, Molecule, Organelle, Cells, Tissues, Organ, Organ System, Organism, Population, Community, Ecosystem, and Biosphere.

What are the four categories of Human Body Tissues?

Epithelial Tissue, Connective Tissue, Muscular Tissue, and Nervous Tissue.

How is a biological population defined?

All the individuals of one species living in a specific area at one point in time.

What is the difference between a community and an ecosystem?

A Community consists of more than one population of organisms living in one place at one time, whereas an Ecosystem includes the Community plus physical components (such as temperature, rainfall, and space) with which the organisms interact.

How does the study guide define metabolism and homeostasis?

Metabolism is the set of all biochemical reactions that sustain life inside each cell and organism. Homeostasis means "staying the same" and is the ability of an organism to maintain its internal conditions within a narrow set of parameters.

What is the definition of evolution given in Chapter 1?

Evolution is the change in genetic make-up of a population over multiple generations.

What are the three domains of life and their defining cell characteristics?

Domain Bacteria (widespread unicellular prokaryotes lacking a nucleus), Domain Archaea (unicellular prokaryotes often living in extreme environments), and Domain Eukarya (eukaryotic organisms whose cells contain a nucleus).

What are the eight hierarchical levels of taxonomy in order from broadest to most specific?

Domain, Kingdom, Phylum, Class, Order, Family, Genus, and species.

What is the complete taxonomic classification of the domestic housecat, Felis catus?

Domain Eukarya, Kingdom Animalia, Phylum Chordata, Class Mammalia, Order Carnivora, Family Felidae, Genus Felis, and species catus.

What formula is given for calculating mass in Chapter 2?

$$\text{mass} = \text{weight} \times \text{gravity}$$

What are the three subatomic particles of an atom, their charges, and their locations?

Protons (positively charged) in the Nucleus, Neutrons (electrically neutral) in the Nucleus, and Electrons (negatively charged) revolving around the nucleus in Orbitals or Electron Shells.

What is the difference between an atom's Atomic Number and its Mass Number?

An atom's Atomic Number is its number of protons. Its Mass Number (or Atomic Mass) is its total number of protons plus neutrons.

How can measuring the ratio of $C^{14}$ to $C^{12}$ be used to date fossils?

Because the rate of radioactive decay from $C^{14}$ to $C^{12}$ is known, measuring the ratio of $C^{14}:C^{12}$ can accurately date fossils younger than about $50{,}000\,\text{years}$.

What is the difference between a Cation and an Anion?

A Cation is an ion with a positive electrical charge resulting from the loss of an electron. An Anion is an ion with a negative electrical charge resulting from the gain of an electron.

How do Sodium and Chlorine form an ionic bond in table salt (NaCl)?

Sodium ($\text{Na}$, Atomic Number 11) transfers its 1 outermost electron to Chlorine ($\text{Cl}$, Atomic Number 17), resulting in a positively charged $\text{Na}^+$ Cation and a negatively charged $\text{Cl}^-$ Anion that attract each other.

What is the difference between non-polar covalent bonds and polar covalent bonds?

Non-polar covalent bonds feature equal sharing of electrons between atoms of equal electronegativity, forming symmetrical molecules. Polar covalent bonds feature unequal electron sharing because one atom is more electronegative, forming asymmetrical molecules with partial charges.

What is a calorie (little c) as defined in Chapter 2?

The amount of energy required to raise the temperature of $1\,\text{g}$ of water by $1\,^\circ\text{C}$.

How are cohesion, adhesion, and surface tension defined for water?

Cohesion is water sticking to itself, adhesion is water sticking to other objects, and surface tension is a measure of how difficult it is to break the surface of a liquid.

What is the Cohesion-Tension Theory of Xylem Transport?

It describes how plants release water vapor out of their leaves through Transpiration, enabling the plant to pull more water from soil into roots and up through the stem against gravity.

How does concentration change with each unit on the logarithmic pH scale?

Each pH unit represents a tenfold ($10\times$) change in $H^+$ concentration. For example, a substance with a pH of 5 is 100 times ($10 \times 10$) more acidic than one with a pH of 7.

What is a buffer and how does it maintain pH?

A buffer is a substance that minimizes changes in pH by accepting $H^+$ when it is in excess and donating $H^+$ when it is depleted.

What three six-carbon monosaccharides are isomers of each other?

Glucose ("blood sugar" or "photosynthetic sugar"), Fructose ("fruit sugar"), and Galactose (1/2 of "milk sugar").

Which monosaccharides combine via dehydration reactions to form Sucrose, Maltose, and Lactose?

Sucrose is formed by Glucose and Fructose; Maltose is formed by two Glucose monomers; Lactose is formed by Galactose and Glucose.

What are the structures and functions of Amylose, Glycogen, Cellulose, and Chitin?

Amylose (Starch) is used by plants for energy storage; Glycogen is used by animals for energy storage; Cellulose forms plant cell walls; Chitin forms insect and crustacean exoskeletons as well as fungal cell walls.

What is denaturation and what causes it in proteins?

Denaturation is the process where a polypeptide chain unravels, loses its shape, and loses its function. It can be caused by changes in salt concentration, pH, or high heat.

What are the four levels of protein structure?

Primary structure (unique amino acid sequence), Secondary structure (coiling/folding), Tertiary structure (overall 3D shape), and Quaternary structure (association of two or more polypeptide subunits, such as Collagen).

What three parts make up a nucleotide monomer?

A five-carbon sugar (Ribose in RNA or Deoxyribose in DNA), a Phosphate group, and a Nitrogenous base.

What are the functions of mRNA, rRNA, and tRNA in protein synthesis?

mRNA carries the genetic message from the Nucleus to the Ribosome; rRNA forms part of the Ribosome where mRNA is read; tRNA matches up to mRNA and delivers amino acids in sequence to build the primary structure of a protein.

How do saturated, unsaturated, and polyunsaturated fats differ?

Saturated fats have maximum hydrogen atoms and no double bonds, making them solid at room temperature. Unsaturated fats have double bonds causing kinks in the carbon chain, making them liquid at room temperature. Polyunsaturated fats have multiple double/triple bonds, making them the lightest fats.

How are phospholipids arranged in a cell membrane?

They cluster into a bilayer with hydrophilic phosphate "heads" facing the outside and inside of the cell membrane, and hydrophobic fatty acid "tails" facing each other in the center.