AP Bio Semester 1 Final

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chloroplast

organelle found in cells of plants and some other organisms that captures the energy from sunlight and converts it into chemical energy

thylakoids

disk-shaped structures within a chloroplast that serve as the site for light harvesting in photosynthesis

grana

a stack of thylakoids within a chloroplast

stroma

region outside the thylakoid membranes in chloroplasts

mitochondria

Powerhouse of the cell, organelle that is the site of ATP (energy) production

mitochondrial matrix

The compartment of the mitochondrion enclosed by the inner membrane and containing enzymes and substrates for the Krebs cycle.

cristae

Infoldings of the inner membrane of a mitochondrion that houses the electon transport chain and the enzyme catalyzing the synthesis of ATP.

inner mitochondrial membrane

The membrane of the mitochondria that is the site of electron transport and chemiosmosis.

outer mitochondrial membrane

the smooth membrane covering the outside of a mitochondrion

Golgi apparatus

An organelle in eukaryotic cells consisting of stacks of flat membranous sacs that modify, store, and route products of the endoplasmic reticulum.

cis end of Golgi apparatus

located near ER, acts as receiving department

trans end of Golgi apparatus

gives rise to vesicles, acts as shipping department

vesicles

small membrane sacs that specialize in moving products into, out of, and within a cell

free ribosomes

scattered throughout the cytoplasm, the proteins they manufacture enter the cytosol

bound ribosomes

attached to outside of ER or nuclear envelope- proteins that are destined for insertion into membranes or packaging certain organelles (ex: lysosome)

lysosome

membrane-bound sac containing digestive enzymes that can break down proteins, nucleic acids, and polysaccharides

endoplasmic reticulum

a cell structure that forms a maze of passageways in which proteins and other materials are carried from one part of the cell to another

cell wall

a rigid layer of nonliving material that surrounds the cells of plants and some other organisms

vacuole

a water-filled sac inside a cell that acts as a storage area

peroxisome

organelle with various specialized metabolic functions; produces hydrogen peroxide

microfilament

(actin filaments), two intertwined strands of actin, functions in mainenance of cell shape, changes in cell shape, muscle contraction, cell motility, cell division

microtubules

(tubulin polymers), hollow tubes, function in maintenance of cell shape, cell motility, chromosome movements in cell division, organelle movements

intermediate filaments

fibrous proteins supercoiled into thicker cables, (keratin), maintenance of cell shape, anchorage of organelles like nucleus, formation of nuclear lamina

plasmodesmata

Open channels in the cell wall of a plant through which strands of cytosol connect from an adjacent cell.

tight junctions

membranes of neighboring cells are actually fused forming continuous belts around cell to prevent leakage of extracellular fluid

desmosomes

Points in which two cells are fastened together into strong sheets. Intermediate filaments anchor these. Also called anchoring junctions.

gap junctions

provide cytoplasmic channels between adjacent animal cells

cholesterol's function in fluid mosaic model

wedged between phospholipid molecules in plasma membranes of animal cells, "temperature buffer"

fibers of extracellular matrix function in fluid mosaic model

attach to peripheral proteins; help maintain cell shape & stabilizes location of membrane proteins

glycolipid function in fluid mosaic model

covalently bonded to lipids, functions as marker that distinguishes one cell from another

integral protein function in fluid mosaic model

penetrate hydrophobic core of lipid bilayer, function in transport, enzymatic activity, signal transduction, cell-cell recognition, and intercellular junction

peripheral protein function in fluid mosaic model

not embedded in bilayer, attach to cytoskeleton and ECM

glycoprotein function in fluid mosaic model

covalently bonded to proteins, functions as marker that distinguishes one cell from another

phospholipid bilayer function

amphipathic molecule (hydrophobic region and hydrophilic region), fluidity, movement

osmosis

diffusion of molecules through a semipermeable membrane from a place of higher concentration to a place of lower concentration until the concentration on both sides is equal

diffusion

the process by which molecules move from an area of higher concentration to an area of lower concentration

facilitated diffusion

the transport of substances through a cell membrane along a concentration gradient with the aid of carrier proteins

active transport

energy-requiring process that moves material across a cell membrane against a concentration difference

sodium potassium pump

a carrier protein that uses ATP to actively transport sodium ions out of a cell and potassium ions into the cell

catabolic

A process in which large molecules are broken down

anabolic

A process in which large molecules are built from small molecules

cellular respiration

the process that releases energy by breaking down glucose and other food molecules in the presence of oxygen

glycolysis

a metabolic process that breaks down carbohydrates and sugars through a series of reactions to either pyruvic acid or lactic acid and release energy for the body in the form of ATP

citric acid cycle

in cellular respiration, series of chemical reactions that break down glucose and produce ATP; energizes electron carriers that pass the energized electrons on to the electron transport chain

electron transport chain

a series of molecules, found in the inner membranes of mitochondria and chloroplasts, through which electrons pass in a process that causes protons to build up on one side of the membrane

chemiosmosis

An energy-coupling mechanism that uses energy stored in the form of a hydrogen ion gradient across a membrane to drive cellular work, such as the synthesis of ATP. Most ATP synthesis in cells occurs by this

ATP synthase

protein structure in cell mitochondria that uses energy from H+ ions to convert ADP to ATP

alcoholic fermentation

anaerobic process in which cells convert pyruvic acid into carbon dioxide and ethyl alcohol; carried out by many bacteria and fungi such as yeasts

lactic acid fermentation

series of anaerobic chemical reactions in which pyruvic acid uses NADH to form lactic acid and NAD+, which is then used in glycolysis; supplies energy when oxygen for aerobic respiration is scarce

oxidation

The loss of electrons from a substance involved in a redox reaction.

reduction

The addition of electrons to a substance involved in a redox reaction.

NAD+

an organic molecule that serves as an electron carrier by being oxidized to NAD+ and reduced to NADH

FAD

electron acceptor in the krebs cycle

autotroph

organism that can capture energy from sunlight or chemicals and use it to produce its own food from inorganic compounds; also called a producer

heterotroph

organism that obtains energy from the foods it consumes; also called a consumer

light reactions

The steps in photosynthesis that occur on the thylakoid membranes of the chloroplast and that convert solar energy to the chemical energy of ATP and NADPH, evolving oxygen in the process.

Calvin cycle

reactions of photosynthesis in which energy from ATP and NADPH is used to build high-energy compounds such as sugars

centromere

the region of the chromosome that holds the two sister chromatids together during mitosis

mitosis

cell division in which the nucleus divides into nuclei containing the same number of chromosomes; produces same number of cells started with

centrosome

Central microtubule organizing center of cells. In animal cells, it contains two centrioles.

centriole

in animal cells, a cytoplasmic organelle that organizes the mitotic spindle fibers during cell reproductions

aster

star-shaped structure formed in the cytoplasm of a cell having fibers like rays that surround the centrosome during mitosis

sister chromatids

Replicated forms of a chromosome joined together by the centromere and eventually separated during mitosis or meiosis II.

daughter chromosomes

Sister chromatids that are separated by mitosis

interphase G1

part of cell cycle when cell grows to normal size and makes organelles

interphase S

synthesis: DNA is replicated, cell now has 2 copies of DNA; each chromosome is copied, new copy is joined w/ old copy, identical copies - sister chromatids

interphase G2

Period after DNA replication; cell prepares for division

mitosis prophase

first and longest phase of mitosis, chromatin condenses into chromosomes and becomes visable, centrioles separate and move to opposite sides of the nucleus, spindle begins to form, nucluer envelope bracks down

mitosis metaphase

second stage of mitosis where chromosomes line up across the center of the cell, mictotubles connect the centromere of each chromosome to the 2 poles of the spindle

mitosis anaphase

third phase of mitosis where sister chromatids separate into individual chromosomes and are moved apart into two groups near the poles of the spindle, phase ends when chromosomes stop moving

mitosis telophase

fourth and final stage of mitosis, distinct and condensed chromosomes begin to disperse into a tangle of dense material, nucleqar envelope re-forms around each cluster of chromosomes, spindle begins to break down, nucleolus becomes visable in each daughter nucleus- mitosis complete, but not cell division

cytokinesis

division of the cytoplasm during cell division

diploid cell

A cell containing two sets of chromosomes (2n), one set inherited from each parent.

haploid cell

A cell containing only one set of chromosomes (n).

meiosis

a process in cell division during which the number of chromosomes decreases to half the original number by two divisions of the nucleus, which results in the production of sex cells; produces4 haploid cells

synapsis

the side by side pairing of homologous maternal and paternal chromosomes at the start of meiosis

tetrad

the four chromatids in a pair of homologous chromosomes that come together as a result of synapsis during meiosis

independent assortment

the random distribution of the pairs of genes on different chromosomes to the gametes

meiosis interphase

chromosomes replicate. each produces 2 sister chromatids, which pair up. Synapsis, Stage that is no different than that of mitosis where the DNA duplicates and the chromosomes are not clearly discerned

meiosis prophase I

2nd stage of meiosis I; chromosomes condense and pair up to form tetrads and attach to spindles; Crossing over between the homologs(the exchange of genetic material b/w non-sister chromatids). The homologs pair up and exchange genes.

meiosis prophase II

1st stage of meiosis II, 6th stage of meiosis; new spindle forms and attaches to the centromeres

meiosis metaphase I

3rd stage of meiosis I; the tetrads line up in the middle of the cell

meiosis metaphase II

7th stage of meiosis, 2nd stage of meiosis II; chromosomes line up across center of cell, spindle fibers attach to each sister chromatid

meiosis anaphase I

4th stage of meiosis I; spindle fibers pull the homologs to opposite sides of the cell. Centromeres don't divide- the chromatids remain connected

meiosis anaphase II

8th stage of meiosis, 3rd stage of meiosis II; centromeres divide, sister chromatids separate and move to opposite poles.

meiosis telophase I

A nuclear envelopes form around the chromosomes. Chromosomes uncoil. Spindles disappear.

meiosis telophase II

9th and last stage of meiosis, 4th stage of meiosis II; nucleus reforms, cytokinesis occurs. Chromoatids are now chromosomes. Result is four haploid cells

homozygous

term used to refer to an organism that has two identical alleles for a particular trait

heterozygous

term used to refer to an organism that has two different alleles for the same trait

multiple alleles

three or more forms of a gene that code for a single trait

co-dominance

situation in which both alleles of a gene contribute to the phenotype of the organism

incomplete dominance

creates a blended phenotype; one allele is not completely dominant over the other

pleiotrophy

A single gene that affects more than one trait

epistasis

a gene at one locus alters the phenotypic expression of a gene at a second locus

x-linked

the pattern of inheritance that results from genes located on the X chromosome

test cross

the crossing of an individual of unknown genotype with a homozygous recessive individual to determine the unknown genotype

nondisjunction

error in meiosis in which homologous chromosomes don't separate; gametes end up with wrong number of chromosomes

translocation

change to a chromosome in which a fragment of one chromosome attaches to a nonhomologous chromosome

deletion

occurs when a chromosomal fragment lacking a centromere is lost

inversion

a chromosomal fragment may also reattach to the original chromosome but in the reverse orientation