enzyme and cell divison

reasons for cell divison

asexual reproduction, growth and development, replace and repair cells

binary fission

splittign of one parent cell into 2 identical daughter cells (chromosome duplication, cell growth, fission)

interphase

first step of cell division, preparation for eukaryotic cells division

G1

interphase period of cell growth

S

interphase period of DNA synthesis; each chromosome is copied and a centromere bond attachess the copy to the original

G2

interphase period of mass cell structure production; duplicated chromosomes become 2 sister chromatids bonded by a centromere with kinetochore fibers extended from them

mitotic phase

second stage of cell division

prophase

first step of mitotic phase where chromosomes become thick, the nucleolus disappears, the nuclear envelope breaks down, and the mitotic spindle forms

mitotic spindle

arrangement of microtubules called spindle fibers, attached to centrioles in animal cells

metaphase

second stage of mitotic stage, lining up of duplicated chromosomes along the middle of the cell at the equator/metaphase plate

anaphase

third stage of the mitotic stage where sister chromatids pull apart to opposite ends of the cell, spindle fibers shorten and break

telophase

fourth stage of the mitotic stage that forms 2 new nuclei for daughter chromosomes, the nuclei appear, the mitotic spindle dissapears, and chromosomes thin and decondense into chromatin

cytokinesis

division of parent cell

cleavage furrowing

in animal cells, a contracting ring of microfilaments pulls inwardly on the cell membrane

cell plate formation

in plant cells, golgi vesicles of cellulose line up a long the middle of a cell and fuse to form new walls

metabolism

sum of all chemical reactoins

catabolism

reactions involved in breaking down molecules

anabolism

reactions that involve building molecules

exergonic

reactions that yield more energy than required

endergonic

reactions that require more energy than what is yielded

enzymes

regulate chemical reactions and lower activaction energy; they only act upon certain substrates, which are reactants that are acted upon by an enzyme

active site

region an enzyme and substrate binds

cofactor

inorganic material that attaches to an enzyme and allows it to accept substrate

coenzyme

organic vitamins that attach to an enzyme and allows it to accept substrate

enzyme inhibition

stops enzyme temporarily by preventing binding

competitive enzyme inhibition

molecule binds to active site of the enzyme

noncompetitive inhibition

molecule binds to another spot

factors that affect enzyme activity

longer time, specific substrate shape, substrate concentration, enzyme concentration, temperature, pH, salinity