slcc biol1610 review final

diploid

cell, nucleus, or organism containing two sets of chromosomes (2n)

haploid

cell, nucleus, or organism containing one set of chromosomes (n)

gamete

haploid reproductive cell (sperm or egg) that fuses with another haploid cell during fertilization

zygote

a cell formed by the union of two gametes; the first cell of a new individual

allele

one of two or more versions of a gene

phenotype

observable traits of an organism

genotype

underlying genetic makeup of an organism

P0

parental generation

F1

first filial generation in a cross; the offspring of the parental generation

F2

second filial generation produced when F1 individuals are self-crossed or crossed with each other

recessive

trait that appears "latent" or non-expressed when the individual also carries a dominant trait for that same characteristic; when present as two identical copies, the recessive trait is expressed

dominant

trait which confers the same physical appearance whether an individual has two copies of the trait or one copy of the dominant trait and one copy of the recessive trait

law of segregation

paired unit factors (i.e., genes) segregate equally into gametes such that offspring have an equal likelihood of inheriting any combination of factors

homozygous

having two identical alleles for a given gene on the pair of homologous chromosomes

heterozygous

having two different alleles for a given gene on the pair of homologous chromosomes

product rule

probability of two independent events occurring simultaneously can be calculated by multiplying the individual probabilities of each event occurring alone

sum rule

probability of the occurrence of at least one of two mutually exclusive events is the sum of their individual probabilities

monohybrid cross

a cross between two true-breeding parents that express different traits for one characteristic

linkage

phenomenon in which alleles that are located in close proximity to each other on the same chromosome are more likely to be inherited together

crossover

exchange of genetic material between homologous chromosomes resulting in chromosomes that incorporate genes from both parents of the organism

incomplete dominance

when the phenotype of the heterozygote displays a distinct, intermediate phenotype between the two homozygotes

codominance

in a heterozygote, complete and simultaneous expression of both alleles for the same characteristic

autosome

any of the non-sex chromosomes

hemizygous

presence of only one allele for a characteristic, as in X-linkage; hemizygosity makes descriptions of dominance and recessiveness irrelevant

autosomal

trait or condition that is transmitted on one of the autosomes (chromosomes that are not sex chromosomes)

sex-linked

trait or condition transmitted on one of the sex chromosomes (in mammals, usually the X chromosome)

dominant

trait which confers the same physical appearance whether an individual has two copies of the trait or one copy of the dominant trait and one copy of the recessive trait

recessive

trait that appears "latent" or non-expressed when the individual also carries a dominant trait for that same characteristic; when present as two identical copies, the recessive trait is expressed

epistasis

antagonistic interaction between genes such that one gene masks or interferes with the expression of another

polygenic inheritance

inheritance of a trait controlled by more than one gene

autotroph

an organism that obtains carbon from inorganic molecules, such as carbon dioxide

heterotroph

an organism that obtains its carbon from organic molecules

photosynthesis

process of converting light energy into chemical energy

anabolic

reaction or pathway that requires an input of energy to synthesize complex molecules from simpler molecules

catabolic

reaction or pathway in which complex molecules are broken down into simpler ones

thermodynamics

study of energy and energy transfer involving physical matter

entropy

measure of randomness or disorder within a system

energy

the ability to do work

kinetic energy

energy of objects or particles due to their motion

potential energy

energy type that has the potential to do work; stored energy

chemical energy

potential energy in chemical bonds that releases when those bonds are broken

Gibbs free energy

Gibbs free energy is the energy that is available to do work (delta G)

exergonic

describes chemical reactions that release free energy

endergonic

describes chemical reactions that require energy input

adenosine triphosphate

the energy currency molecule of cells; provides energy for most biological reactions that require an input of energy

energy coupling

process during which energy released by an exergonic reaction is used to drive an endergonic reaction

enthalpy

the total energy of a system

heat

energy transferred from one system to another that is not work (energy of the molecules' motion or particles)

Photosynthesis

process of converting light energy into chemical energy

Cellular respiration

metabolic pathway that breaks down glucose and other food molecules to produce ATP

Anabolic

reaction or pathway that requires an input of energy to synthesize complex molecules from simpler molecules

Endergonic

describes chemical reactions that require energy input

Catabolic

reaction or pathway in which complex molecules are broken down into simpler ones, releasing energy

Exergonic

describes chemical reactions that release free energy

Chemiosmosis

movement of ions down their gradient through a membrane protein; usually refers to the process that produces ATP by harnessing the energy of protons flowing down their gradient which powers ATP synthase

Potential energy

energy type that has the potential to do work; stored energy

Oxidation

loss of electrons

Reduction

gain of electrons

Redox reaction

reaction in which an electron is transferred between two substances

Aerobic respiration

process in which organisms convert energy in the presence of oxygen

Electronegativity

ability of an atom to attract electrons

Cellular respiration

metabolic pathway that breaks down glucose and other food molecules to produce ATP

Aerobic respiration

process in which organisms convert energy in the presence of oxygen

Electron carrier

a molecule capable of accepting one or two electrons from one molecule and donating them to another molecule

Electron transport chain

a series of proteins and other molecules that transfer electrons from electron donors to electron acceptors through a series of redox reactions, coupling the energy released with active transport of hydrogen ions (H+)

Mitochondria

(singular = mitochondrion) cellular organelles responsible for carrying out cellular respiration. Originally derived from proteobacteria via endosymbiosis.

Matrix

the fluid-filled space inside the inner membrane of the mitochondrion

Intermembrane space

the fluid-filled space between the outer membrane and the inner membrane of the mitochondrion

Glycolysis

process of breaking glucose into two three-carbon molecules with the production of ATP and NADH

Fermentation

an anaerobic process that quickly generates an additional ATP through the reduction of pyruvate

Acetyl CoA

combination of an acetyl group (two carbons) derived from pyruvate and coenzyme A

Pyruvate

three-carbon sugar that can be decarboxylated and oxidized to make acetyl CoA, which enters the citric acid cycle under aerobic conditions; the end product of glycolysis

Pyruvate oxidation

the conversion of pyruvate into an acetyl group, which takes place when electrons from pyruvate are transferred to NAD+

Citric acid cycle

(also Krebs cycle) series of enzyme-catalyzed chemical reactions that completes glucose catabolism during cellular respiration

Photosynthesis

process of converting light energy into chemical energy

Autotroph

an organism that obtains carbon from inorganic molecules, such as carbon dioxide

Heterotroph

an organism that obtains its carbon from organic molecules

Mesophyll

middle layer of chlorophyll-rich cells in a leaf

Stoma (pl. stomata)

opening that regulates gas exchange and water evaporation between leaves and the environment, typically situated on the underside of leaves

Chloroplast

organelle in which photosynthesis takes place

Thylakoid

disc-shaped, membrane-bound structure inside a chloroplast where the light-dependent reactions of photosynthesis take place

Thylakoid membrane

membrane around the thylakoids, which are found within chloroplasts

Thylakoid lumen

the fluid-filled space within the thylakoid membrane

Stroma

the fluid-filled space inside a chloroplast but outside of the thylakoids

electromagnetic radiation

range of all possible frequencies of radiation

pigment

molecule that is capable of absorbing certain wavelengths of light and reflecting others (which accounts for its color)

carotenoid

photosynthetic pigment (yellow-orange-red) that functions to dispose of excess energy

chlorophyll b

accessory pigment that absorbs blue and red-orange light and consequently has a yellowish-green tint

chlorophyll a

form of chlorophyll that absorbs violet-blue and red light and consequently has a bluish-green color

photosystem

group of proteins, chlorophyll, and other pigments that are used in the light-dependent reactions of photosynthesis to absorb light energy and convert it into chemical energy

photosystem II (PSII)

integral protein and pigment complex in thylakoid membranes that transports electrons from water to the electron transport chain; oxygen is a product of PSII

photosystem I (PSI)

integral pigment and protein complex in thylakoid membranes that uses light energy to transport electrons from plastocyanin to NADP+ (which becomes reduced to NADPH in the process)

antenna proteins

pigment molecule that directly absorbs light and transfers the energy absorbed to other pigment molecules

reaction center

complex of chlorophyll molecules and other organic molecules that is assembled around a special pair of chlorophyll molecules and a primary electron acceptor; capable of undergoing oxidation and reduction

Calvin cycle

light-independent reactions of photosynthesis that convert carbon dioxide from the atmosphere into carbohydrates using the energy and reducing power of ATP and NADPH

light-dependent reactions

first stage of photosynthesis where certain wavelengths of the visible light are absorbed to form two energy-carrying molecules (ATP and NADPH)

RuBisCO

ribulose-1,5-bisphosphate carboxylase-oxygenase; the enzyme that fixes carbon from the atmosphere and binds carbon dioxide to RuBP