Comparative animal phys exam 1

Acute changes

Short-term changes in the physiology of individual animals: changes that individuals exhibit soon after their environments have changed. Acute changes are reversible.

Chronic changes (termed acclimation and acclimatization; also termed phenotypic plasticity or phenotypic flexibility)

Long-term changes in the physiology of individual animals: changes that individuals display after they have been in new environments for days, weeks, or months. Chronic changes are reversible

Evolutionary changes

Changes that occur by alteration of gene frequencies over the course of multiple generations in populations exposed to new environments.

Developmental changes

Changes in the physiology of individual animals that occur in a programmed way as the animals mature from conception to adulthood and then to senescence

Changes controlled by periodic biological clocks

Changes in the physiology of individual animals that occur in repeating patterns (e.g., each day) under control of the animals’ internal biological clocks

Changes in physiology that are internally programmed to occur whether or not the external environment changes

Developmental and changes controlled by biological clocks

Changes in physiology that are responses to changes in the external environment

Acute, chronic, and evolutionary

Krogh Principle

For every defined physiological problem there is an animal (model) that is ideally suited to help one explain that problem

Eric Kindle Sea slug

simple nervous system can learn and remember, used to study serotonin

Physiology seeks to answer two central questions about how animals work

(1) What is the mechanism by which a function is accomplished, and (2) how did that mechanism come to be?

Chronic responses

are expressed following prolonged exposure to new environmental conditions.

comparative method

seeks to identify adaptive traits by comparing how a particular function is carried out by related and unrelated species in similar and dissimilar environments.

genetic drift

chance assumes a preeminent role in altering gene frequencies

nonadaptive evolution

Because of chance, an allele that provides a lower probability of survival and reproduction than an available alternative comes to be the predominant allele in the population

phenotypic plasticity

the ability of an individual animal (a single genotype) to express two or more genetically controlled phenotypes

allosteric activation

the binding of an allosteric modulator to its binding site on an enzyme molecule increases the affinity of the molecule’s active sites for the substrate or otherwise increases the catalytic activity of the enzyme

allosteric inhibition

the binding of an allosteric modulator impairs the catalytic activity of an enzyme, such as by decreasing its affinity for substrate

allosteric modulation

modulation of the catalytic properties of an enzyme by the binding of nonsubstrate ligands to specific nonsubstrate-binding sites, which are called regulatory sites or allosteric sites

allosteric modulators

The nonsubstrate ligands that participate in this sort of modulation

amphipathic

each molecule consists of a polar part (within which there are regional differences of charge) and a nonpolar part

amplification

occurs because each molecule of an activated protein kinase can catalyze the activation of many molecules of the enzyme following it

Anabolism

the processes that synthesize larger or more complex chemical compounds from smaller chemical building blocks, using energy. Whereas catabolism is destructive, anabolism is constructive

apical surface

facing into a cavity or open space

basal surface

facing toward the underlying tissue

basement membrane

is composed of glycoproteins and particular types of collagen. It is secreted mostly by the epithelial cells, positioned beneath the basal cell surfaces

bioluminescence

The ability of cells to produce light biochemically

brush border

Microvilli are often described collectively as

Five functional types of membrane proteins

channels, transporters (carriers), enzymes, receptors, and structural proteins.

Catabolism

set of processes by which complex chemical compounds are broken down to release energy, create smaller chemical building blocks, or prepare chemical constituents for elimination

catalyst

molecule that accelerates a reaction without, in the end, being altered itself

channels

A membrane protein that aids the passive transport of a solute across a membrane without undergoing any sort of chemical binding with that solute.

transporters (carriers

A membrane protein that mediates the transport of solute molecules across a membrane and must undergo reversible, noncovalent bonding with the solute molecules in order to do so. Transporters participate in facilitated diffusion and active transport

enzymes

A molecule—usually a protein—that catalyzes a chemical reaction in which covalent bonds are made or broken

receptors

A protein that binds noncovalently with specific molecules and, as a consequence of this binding, initiates a change in membrane permeability or cell metabolism. Receptors mediate the response of a cell to chemical messages (signals) arriving from outside the cell

chromatophores

a type of cell containing pigment granules that can undergo changes in dispersion, thereby altering their influence on the color of the skin or other structure; a color-change cell

Constitutive enzymes

An enzyme (or other protein) that is always expressed in a tissue. Contrast with inducible enzyme.

Inducible enzymes

An enzyme (or other protein) that is expressed only when “induced” by the presence of a molecule or condition that serves as an inducing agent

covalent modulation

is the second major way that the function of cells is regulated by changes in the catalytic activity of existing enzymes. Covalent modulation occurs by way of chemical reactions that make or break covalent bonds (strong bonds) between modulators and enzymes