Show Menu
Cheatography

bio110 Cheat Sheet (DRAFT) by

prep for midterms and finals

This is a draft cheat sheet. It is a work in progress and is not finished yet.

Bonds and Polarity

electr­one­gat­ivity
atom's attraction for electrons in a covalent bond (higher when atom more strongly pulls shares electron towards oneself)
polarity
polar when electrons are shared unequally because an atom is more electr­one­gative
hydrogen bonds
form when H covale­ntaly bounds to electr­one­gative atom is also attracted to another electr­one­gative atom -- electr­one­gative partners are usually O or N in living cells

Mendel and the Gene

phenotype
outward appearance
genotypes
allele combin­ation
progeny
descen­dant, offspring
Complete dominance
dominant allele masks recessive allele
incomplete dominance
blending of phenotypes ie pink flower from red and white
codomi­nance
two dominant alleles affect the phenotype in distinct, separate ways
epistasis
traits determined by two or more genes, one gene can alter phenotypic expression of gene at separate locus

polar covalent bonds in water

- polar due to electr­one­gat­ivity of oxygen
- uneven distri­bution of charge
- polarity allows water molecules to form
hydrogen bonds

Properties of Water

Cohesive behaviour
bring water up roots of plants, surface tension
ability to moderate temper­ature
high specific heat capacity due to hydrogen bonds
expansion upon freezing
ice is less dense than water, floats
versat­ility as a solvent
polar dissolves polar

Isomers

structural
different covalent arrang­ements
Cis-Trans
same covalent bonds, differ in spatial arrang­ements
enanti­omers
mirror images of each other

microscopy

light microscope
most used in labora­tories today
scanning electron miscro­scope
useful for studying the topography of a specimen
transm­ission electron microscope
used to study internal structure of cells

Inheri­tance of Diseases (memorize)

Autosomal Dominant: huntington disease, achron­dop­lasia
Autosomal Recessive: Cystic fibrosis, Tay-Sachs, Sickle cell anemia
X-Linked Recessive: colour blindness, Duchenne muscular dystrophy, Hemophilia
 

Carboh­ydrates

- sugars and polymers of sugars
- usually made from multiples of CH2O
- built from monosa­cch­arides

Lipids

- does not form polymers
- hydrop­hobic
- mostly non-polar (hydro­car­bons)
- includers fats, phosph­oli­pids, steroids

Proteins

- made from amino acid chains that are
joined from peptide bonds (carboxyl
group to amino groups)
- catalyze rxns, structure support,
transport, defense, movement
water molecule is released each time a peptide bond is formed (dehyd­ration synthesis)

Phosph­olipids

- hydrophilic head
- hydrophobic tail
- amphip­athic (having hydrop­hilic and phobic
parts
- sponta­neously self-a­ssemble into bilayer
when added to water

sickle cell anemia

- crescent shaped exterior
- abnormal intera­ctions with other sickle­-cells reducing capacity to carry oxygen

plants and some algae

sporophyte
diploid cell that makes haploid spores by meiosis
gameto­phyte
a haploid that spores grow into via mitosis
- haploid cells grow by mitosis into haploid multic­ellular organisms
- haploid adults produce gametes by mitosis

amino acid types

hydrop­hobic
carbon rich side chains(in many membrane bound proteins)
hydrop­hilic
hydrogen bonds
charged
work well with oppositely charged amino acids or other molecules

endosy­mbiont theory

modern eukaryotic cells evolved from prokar­yotic cells that were engulfed by bigger prokar­yotic cells. consistent with theory that all organisms arose from a single common ancestor

other cell structures

peroxisome
contain enzymes that remove hydrogen atoms from various substrates and transfer them to oxygen
centro­somes and centrioles
help organize microt­ubule assembly in animal cells

dna replic­ation

SSB Proteins
keeps dna from coming apart (reann­ealing)
topois­omerase
prevent dna from uncoiling
helicase
breaks apart the hydrogen bonds to separate the DNA strands
DNA polymerase
replicates DNA to build a new one
Ligase
puts together the DNA strands
primase
builds primers (made of RNA) for polymerase to build on
okazaki fragments
sequences of DNA neucle­otides on the lagging strand that will later be bonded together by ligase
 

the nucleus

basic functions
contains most of cell's genes
nuclear envelope
double membrane, each membran consists of a lipid bilayer
nuclear pores
regulate entry and exit of molecules
nuclear lamina
maintains shape of nucleus (composed of protein filaments)

endopl­asmic reticulum

smooth
synthesis lipids, metabolize carboh­ydr­ates, detoxifies poisons, stores calcium ions
rough
site for protein synthesis, produces transport vesiclres that distribute lipids and proteins to other components of the system
- accounts for half of total membrane in the cell
- continuous with nuclear envelope

ATP

golgi apparatus and lysosomes

gogli apparatus
processes and modifies proteins from ER to ship to target locations
lysosomes
compar­tment of enzymes, hydrolyzes proteins, fats, polysa­cch­arides, nucleic acids, work best in acidic enviro­nments

meiosis cell cycle

prophase I
chromo­somes condense, crossing over (synapsis) takes place
metaphase I
tetrads align in center of the cell
anaphase I
chromosome migrate to opposite sides, chromatids are still joined by centro­meres
telophase I
cytoki­nesis occurs, two daughter haploid cells are formed
prophase II
chromo­somes move towards center
Metaphase II
chromo­somes aligned at center, centro­meres facing opposite directions
anaphase II
chromatids separated, move towards poles
telophase II
cytoki­nesis divides into four nuclei, nuclear membrane develops, four daughter cells or gametes are produced
whole process ends with four haploid daughter cells

Abnormal Chromosome numbers

Aneuploidy
when nondis­jun­ction occurs in the fertil­ization of gametes
monosomic zygote
zygote only has one copy of a particular chromosome
trisomic
zygote has three copies of a chromosome (down syndrome)

Aneuploidy of Sex Chromo­somes

XXX
healthy, no unusual physical features
XXY (kline­felter syndrome)
extra X chromosome in males
Monosomy (turner syndrome)
produces XO females who are infertile

cell cycle clock

 

animal cell

plant cell

cell cycle in mitosis

interphase
centro­somes have formed, chromo­somes aren't seen clearly
prophase
chromo­somes condense, mitotic spindle starts to form, microt­ubules lengthen moving centro­somes away from each other
promet­aphase
nuclear envelope fragments, kineto­chore formed on centro­meres
metaphase
chromo­somes align in the center of the cell
anaphase
chromo­somes are split and sister chromatids move to opposite poles
telophase
fibers disappear and membrane reforms around each set
cytoki­nesis
cleavage of cell and its contants divide into 2
cancer occurs when cells don't properly respond to control mechanisms (uncon­trolled mitosis)

subphases of interphase

G1 checkpoint
growth phase: can continue on to other phases once receives go ahead at this stage
S phase
duplic­ation of DNA
cyclins and cycli-­dee­pendent Kinases (Cdk)
always present but fluctuate during cell cycle based on concen­tra­tions of cyclin
G2
final subphase, more growth and protein synthesis
Maturation promoting factor (MPF)
cyclin-Cdk complex that triggers cell passage past G2 phase into M phase
M checkpoint
won't enter anaphase unless chromo­somes are all attatched to spindle microt­ubules at kinete­chores, may delay anaphase to ensure daughter cells receive correct # of chromo­somes
cells grow in all three subphases of interphase but chromo­somes are only duplicated during S phase

Sources of genetic variation

- crossing over during prophase I
- indepe­ndent assortment of chromo­somes
- Random fertil­ization

Mutations

nondis­jun­ction
problem during meiosis that results intoo mayn or too few chromo­somes: down syndrome (trisomy)
deletion
portion of chromo­somes are lost, caused by viruses or chemicals
duplic­ation
gene sequence is repeted one or more times within one or more chromo­somes
inversion
certain gene segments become free and then are reversed
transl­ocation
part of the chromosome changes places with another part

DNA features

nucleotide
phosphate group, 5 carbon sugar, nitrog­enous base
nitrog­enous base
adenine, guanine, thynine, cytosine
phosphate group between 5' and 3'
deoxyn­ucl­eotides
phosph­odi­ester bonds
phosphate group of one nucleotide bonds to the 3/ oxygen of another nucleotide
5' to 3'
on top (watson), runs 3' to 5' on bottom­(crick)
bonds between the two strands
non covalent hydrogen bonds with compli­mentary base (base pairs)
pyrimi­dines
thynin and adenine, single ring structure
purines
guanin and cytosine, double rings
- 2 types of nucleic acids (DNA and RNA)
- DNA provides directions for its own replic­ation
- DNA, RNA, protein

nondis­jun­ction