MCAT

resolution

differentiate close objects

magnification

increase size

eyepiece magnification

10x

objective magnification

4x,10x,20x, 100x

Cell Theory

-all living things composed of cells

-cell=basic functional unit of life

-cells from other cells only

-cells have DNA (parent-->daughter cells)

total magnification

eyepiece x objective

diaphragm (microscope)

controls light

image contrast

hematoxylin

-commonly used dye

-shows nucleic acids (DNA,RNA)

how does the dye hematoxylin show nucleic acids?

binds to the negative sugar-phosphate backbone

phase contrast microscope

-living organisms

-differences in refractive indices among different subcellular structures

electron microscope

-atomic level

-samples must be sliced thinly and impregnated with heavy metals for contrast

prokaryotes

before nuclei (no nuclei)

eukaryotes

after nuclei

types of prokaryotes

bacteria and blue-green algae

prokaryote characteristics

-unicellular

-no nucleus or membrane bound organelles

-cell wall in all

-ability to carry other pieces of DNA

What type of genetic material is present within prokaryotes?

-single circle molecule of DNA

-within nucleoid region

plasmids

-circular DNA

-small

-few genes

-replicate independently

cocci

spherical bacteria

bacilli

rod-shaped bacteria

how do antibacterials work?

tend to attack bacterial specific structures

Eukaryote characteristics

-protists, fungi, plants, and animals

-cell walls in fungi and plants

-nucleus

-unicellular or multicellular

cytoskeleton proteins

-actin filaments

-intermediate filaments

-microtubules

Smallest cytoskeleton proteins

actin filaments

largest cytoskeleton proteins

microtubules

phospholipid bilayer

-hydrophobic nonpolar tail

-hydrophilic polar head

-cholesterol molecules

purpose of cholesterol in phospholipid bilayer

regulate fluidity

transport proteins

-control entry/exit

-polar molecules and ions allowed through

cell adhesion molecule purpose

-CAMs

-allow cells to recognize each other

-proper cell differentiation and development

nucleus membrane

-double membrane

-nuclear membrane/envelope

purpose of nucleolus

ribosomal RNA synthesized (rRNA)

Ribosomes

-protein production

-free and bound types

Endoplasmic Reticulum

-production and sorting of materials from cell

smooth ER purpose

lipid synthesis and detox drugs/poisons

rough ER purpose

protein production

Golgi structure

membrane bound sacs

golgi purpose

-receives from smooth ER

-repackages to cell surface via secretory vescicles

lysosomes

-'garbage dumps'

-receives from endosomes

-uses hydrolytic enzymes at lowered pH

-break down materials

-remove old cell components and replace

-can cause autolysis

autolysis

cell suicide

mitochondria

powerhouse

-2 layers

-semi-autonomous

-inherited only from the mother

2 layers of mitochondria

outer-walls

inner-electron transport chain

what is the purpose of cristae on mitochondria?

increase surface area

semi-autonomous

own genes

-replicate independently

types of microbodies

-peroxisomes

-glyoxysomes

peroxisomes

-create hydrogen peroxide

-break down fats

-catalyze detox

glyoxysomes

-germinating plants

-convert fats to sugars

chloroplasts

-in plants and algae

-powerhouse

-contain chlorophyll

-generation of energy

-own DNA

plant cell wall composition

cellulose

fungi cell wall composition

chitin

animal cell wall composition

no cell wall!!

centrioles

-specialized microtubules

-spindle formation

-no membrane

-in animals not in plants

microfilaments

-rods of actin

-muscular contraction with interaction with myosin

-movement of materials within cell membrane

microtubules

-hollow

-polymers of tubulin

-throughout cell

-transport and structural support

-structural basis for cilia and flagella

intermediate fillaments

integrity of cytoskeleton

osmosis

-water movement

-low solute to high solute

hypotonic solution

-solute inside of cell greater than surrounding

-causes cell to swell

hypertonic solution

-solute inside of cell less than surrounding

What types of materials are impermeable to membrane?

-large

-polar

-charged

pinocytosis

endocytosis of fluids and small particles

phagocytosis

ingestion of large molecules

Molecules through simple diffusion

-small

-nonpolar

-e.g. O2, CO2

Molecules through facilitated diffusion

-large

-nonpolar

-e.g. glucose

Molecules through active transport

-polar

-ions

-e.g. Na+,Cl-,K+

Epithelial tissue

-cover body

-line cavities

-protection, absorption, secretion, and sensation

connective tissue

-supports body

-bone, cartilage, tendons, ligaments, adipose tissue, blood

nervous tissue

-cell signaling

-coordinated control

muscle tissue

-skeletal, smooth, cardiac

viruses characteristics

-acellular

-nucleic acids with protein coat

-has capsid

-

genetic info of viruses

-circular or linear

-single or double stranded

-DNA or RNA

obligate intracellular parasites

express and replicate within a cell

virions

new copies of DNA

capsid

protein coat

Bacteriophages

-viruses that target bacteria

-inject genetics only not entire body

endothermic

requires energy (heat)

exothermic

gives off energy (heat)

enzymes

-lower activation energy

-increase rate

-does not change ΔG or ΔH

-not changed or consumes

-very specific

theories of enzyme mechanism

lock and key

vs.

induced fit

aponzymes

without their cofactors

holoenzymes

with cofactors

cofactors

-prosthetic groups

-small metal ions and small organic groups

coenzymes

cofactors that are small organic groups

Vmax

max velocity

Reactions cannot go any faster once reaching what?

saturation

enzyme affinity

=km

=(1/2)Vmax

low Km means

high affinity

high Km means

low affinity

rate double per 10 degree C increase in temperature until what?

optimum temp

what occurs after optimum temperature is reached?

activity falls sharp

what occurs to enzymes at high temperatures?

it denatures

blood pH

7.4

pH 7.3 indicates:

acidosis

pH values

basic >7>acidic

competitive inhibition

-binds active site

-overcome by adding substrate

-increase Km

noncompetitive inhibition

-binds other than active site

-cannot be overcome

-Km unchanged

-Vmax decreased

zymogens

regulatory domain must be removed/altered to expose active site

autotrophs

-use sun energy to make organic molecules

-do not require organic compounds

heterotrophs

break bonds in organic molecules for energy

Intermediates

-ADP,NAD+,FAD

-high-energy electron shuttles between cytoplasm and mitochondria

ATP aka

adenosine triphosphate

ATP

-primary energy currency of cell

-generated during glucose catabolism

-energy stored in high-energy phosphate bonds

why are ATP phosphate bonds high energy?

it is energetically unfavorable to have negatives close together