Biology

Plant leaf tissue where majority of photosynthesis takes place

Two membranes; Thylakoid membrane contains majority of photosynthetic protein complexes

Light energy captured by pigments; Electron transport chain producing a proton gradient across the membrane

ATP; NADPH; O2

Light reactions; Calvin Cycle

chlorophyll - major pigment

Large membrane protein complexes used to absorb the light energy

splits water molecule to replace electron lost due to light exciting a special pair of chlorophylls

uses electron originating from Photosystem II to replace electron lost due to light exciting a special pair of chlorophylls

Atmospheric carbon dioxide, ATP, and NADPH used to produce organic molecules

product of Calvin Cycle; 3-carbon molecule; used to make glucose, the disaccharide sucrose, and other organic molecules as needed

Double stranded, Deoxyribose sugar, adenine (A) cytosine (C) thymine (T) guanine (G)

Single stranded, Ribose sugar, adenine (A) cytosine (C) uracil (U) guanine (G)

monomer used to make DNA and RNA

1. Phosphate group 2. Sugar molecule 3. Nitrogenous base

Sugar-phosphate backbone; Base perpendicular to backbone

Strands held together by hydrogen bonding between bases; helical; directional - 5’ to 3’

Rosalind Franklin with James Watson and Francis Crick

each new strand bonded to an existing strand; Begins at origins of replication

replication enzyme

continuous

fragments (Okazaki fragments)

seals breaks between Okazaki fragments

DNA ---> RNA ---> Protein

DNA ---> RNA

RNA ---> Protein

DNA sequence typically used to produce a protein product Gene sequence read 3-bases at a time (triplet code) aka codon

64

61; 3 codons are known as “Stop codons” terminating transcription and translation

redundant, unambiguous, and nearly universal

more than one codon for some amino acids

any codon for one amino acid does not code for any other amino acid

the genetic code is shared by organisms from the simplest bacteria to the most complex plants and animals

initiation, elongation, and termination

the attachment of RNA polymerase to the promoter and the start of RNA synthesis

the newly formed RNA strand grows

when RNA polymerase reaches the terminator DNA and the polymerase molecule detaches from the newly made RNA strand and the gene

messenger RNA (mRNA)

entire strand used to translate into protein

contains regions NOT used to translate into protein: Intron and Exon

non-coding regions removed before translation

coding regions

RNA splicing, mRNA cap, Poly-A tail

removal of introns and fusing exons together

added to 5’ end

long chain of adenosines added to 3’ end

transfer RNA (tRNA); Processed mRNA; Ribosome

physically brings amino acids to ribosome for translation; contains anti-codon (matches codon on mRNA to ensure correct amino acid is added

two subunits: large and small ○ composed almost entirely of ribosomal RNA (rRNA)

transformation, transduction, and conjugation

the uptake of DNA from the surrounding environment

gene transfer by phages

the transfer of DNA from a donor to a recipient bacterial cell

a small, circular DNA molecule separate from the bacterial chromosome; replicates independent of the chromosome; can have multiple copies

the turning on and off of genes; occurs at multiple levels

the overall process of information flow from genes to proteins

a cluster of genes with related functions, along with the control sequences

three adjacent lactose-utilization genes; a promoter sequence; an operator sequence

a site where RNA polymerase binds and initiates transcription of all three lactose genes

where a repressor can bind and block RNA polymerase action

located outside the operon, continually codes for a repressor protein

the repressor binds to the operator and prevents RNA polymerase action

the operator is unblocked, RNA polymerase can bind to the promoter, and all three genes of the operon are transcribed

bind directly to DNA and affect whether and how fast a gene is transcribed; Regulate which genes are turned on or off at any given time

bind to promoters or silencers to shut off or slow down transcription

recruit RNA polymerase to a promoter region to enhance transcription

Chromatin: DNA and histones Nucleosome: DNA wrapped around the histone core

Supercoiled nucleosomes physically disrupt gene transcription

Acetylation (addition of acetyl groups) Methylation (addition of methyl groups)

produces different mRNAs from the same transcript and results in the production of more than one polypeptide from the same gene

Small (~25 nucleotides); Complementary to mRNA

Degrade complementary mRNA molecules; Block its translation

set of diseases in which the control mechanisms that normally limit cellular growth have malfunctioned

produces offspring that are identical to the original cell or organism; inheritance of allgenes from one parent

produces offspring that are similar to the parents but show variations in traits; involvesinheritance of unique sets of genes from 2 parents

Cell division in single-celled organisms

Division of a eukaryotic cell’s nucleus

duplication of cell contents •G1—growth, increase in cytoplasm •S—duplication of chromosomes •G2—growth, preparation for division

division •Mitosis—division of the nucleus •Cytokinesis—division of cytoplasm

•prophase •prometaphase •metaphase •anaphase •telophase

● length ● centromere position ● staining pattern ● receive one from each parent

the position of a gene

In humans: 22 sets of chromosomes that are similar in their genetic makeup and size (homologous)

X and Y, determine sex of organism

Occurs in prophase I exchange of corresponding segments between nonsister chromatids of homologous chromosomes

the failure of chromosomes or chromatids to separate normally during meiosis