DAT Biology Study

sphingolipids

lipids with a backbone containing aliphatic (non-aromatic) amino alcohols

helps cell with structural support, signaling transduction, and cell recognitions

glycolipids

found in plasma membrane with carb group bound rather than phosphate group

waxes and carotenoids

waxes: simple lipids with long fatty acid chains connected to alcohol

carotenoids: lipid derivatives containing long carbon chains conjugated double bonds (serve as biological pigments)

Lipoproteins

round complex composed of lipids and proteins that carry lipophilic molecules thru the blood

outside made of phospholipids, cholesterol, proteins

carry cholesterol and proteins through blood, different types carry different ratios

phospholipid

one phosphate group attached to the glycerol backbone with two fatty acid tails

Competitive inhibitor

Km increases, Vmax doesn’t change when substrate added

non-competitive inhibitor

Km stays the same, Vmax decreases

Holoenzyme

complex that forms when enzyme binds to cofactor

(Apoenzyme: enzyme without a bound cofactor)

Secondary protein

held together by intermolecular forces between peptide backbones and hydrogen bonds

Tertiary protein

held together by interactions from R groups, disulfide bonds, hydrophobic interactions, hydrogen bonds and ionic bonds between R groups

Quaternary structure

held together by interactions between multiple polypeptide subunits

Isoelectric Series

group of elements/ions that has the same number of electrons

Desmosomes

type of cell junction that provides cell-cell adhesion and mechanical stability

Gastrulation

stage of embryonic development which germ layers form

Resource partitioning

species within the same ecosystem that adapt to minimize competition for shared resources by occupying different realized niches. reduces indirect competition

fundamental niche

full range of environmental conditions in which a species could theoretically survive in absence of competition and other limiting factors

realized niche

actual conditions and resources a species uses in the presence of competition

Habituation

form of learned behavior that occur when animal minimizes its response to a stimulus that ishas no consequence

sensitization

animal learns to react more often or move more strongly to repeated stimulus

Don’t kiss Paul’s cousin or frick Gary’s sister

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

microfilaments

cell movement

muscle contraction

Protein = Actin

generates a cleavage furrow with a contractile ring

smallest diameter, double helix

cyclosis: actin and myosin stir cytoplasm

intermediate filaments

Protein = keratin

stable structural component

microtubules

centrioles

protein = tubulin

cilia and flagella with cell movement

Kinesin and dynein proteins walk down to transfer things within a cell

integrins

transmembrane proteins that control adhesion and signals

fibronectin

signals transduction

laminin

cell differentiation, adhesion, and movement

Extracellular Matrix

composed of proteins and glycoproteins that support the space between cells

proteoglycan: lots of carbs, has a negative charge to attract water

collagen: secreted by fibroblasts, most common

Cell walls

plans use cellulose

fungi use chitin

bacteria use peptidoglycan

archaea use polysaccharides

focal adhesions

Actin microfilaments attach EMC to inside of cell

hemidesmosomes

intermediate filaments attach EMC to inside of cell

tight junctions

watertight seals between cells, pass materials directly to neighbor

gap junctions

adhere to neighbor through connexons (type of transmembrane protein)

found in heart

desmosomes

use intermediate filaments, very strong connection, cardiac cells

adherens junctions

actin filaments link cytoskeletons

Plant Junctions

middle lamella: cell walls adhere

plasmodesmata: connections that allow cytosol fluid to travel between

epithelial tissue

sheet of cells that lines organs and body

function in protection, absorption, secretion, sensation

connective tissue

cells within extracellular matrix, provide structure, support, protection

ex. cartilage, bone, blood, adipose

muscle tissue

skeletal, cardiac, smooth

locomotion

nervous tissue

neurons and glial cells

Glycolysis

produces 2ATP + 2NADH + 2 pyruvate

Glycolysis

takes place in cytosol, does not require oxygen

energy investment phase

glucose → fructose-1,6-biphosphate

hexokinase

glucose → glucose-6-phosphate

uses 1 ATP

isomerase

glucose-6-phosphate → fructose-6-phosphate

phosphofructokinase

fructose-6-phosphate → fructose-1,6-biphosphate

uses 1 ATP

key regulatory element because this part takes the longest time in reaction

energy payoff phase

fructose-1,6-biphosphate → 2 glyceraldehyde 3-phosphate → 2 pyruvates

NAD+ is reduced

G3P is oxidized

2 NADH + 4 ATP + 2 pyruvates

Pyruvate Decarboxylation

produces CO2 + NADH + acetyl-CoA

occurs in mitochondrial matrix

x2 for every glucose

pyruvate dehydrogenase enzyme

1) decarboxylation: CO2 removed

2) oxidation: 2-carbon molecule oxidized by NAD+ forms acetyl

3) coenzyme A binds acetyl

Krebs Cycle

produces 2CO2 + 3NADH + FADH2 + ATP

occurs in mitochondrial matrix

x2 for every glucose

Citric Acid Cycle

1) acytyl-CoA joins oxaloacetate to form citrate

2) citrate rearanges to produce CO2 and NADH, this occurs twice to produce a 4 carbon molecule

3) substrate lcl phosphorlylation produces 1ATP

4) FADH reduced to FADH2

5) NAD+ reduced to NADH and 4 carbon molecule converted back to oxaloacetate

Oxidative Phosphorylation

electron transport chain: 4 protein complexes oxidize NADH and FADH2 and set up an electrochemical gradient. H+ flow to intermembrane space

chemiosmosis: ATP synthase protein uses proton gradient to power ATP production, protons flow from intermembrane space to mitochondrial matrix

final electron acceptor

O2

4H+ + O2 + 4e- → 2H2O

FADH

only pumps to protein complex 2 making it produce less effective than NADH

fermentation

Anaerobic respiration that only produces ATP through substrate level phosphorylation. Occurs in cytosol

pyruvate is converted to a different molecule to regenerate NAD+

lactic acid fermentation produces 2 lactate from glycolysis

alcohol fermentation produces 2 ethanol from glycolysis

glycogenolysis

breakdown of glycogen directly into glucose-6-phosphate

uses one less ATP

lipolysis

breaks triglycerides into alcohols and free fatty acids

beta-oxidation

turns free fatty acids into acetyl-CoA

occurs in the mitochondrial matrix

Photosynthesis C3

endergonic and nonspontaneous

carbon fixation → inorganic to organic conversion

Leaf anatomy

epidermis: protection and prevents water loss

palisade mesophyll: many chloroplasts

spongy mesophyll: loose arrangement allowing gas exchange

guard cells: regulate the opening and closing of stomata

stomata: pores for gas exchange

Chloroplast structure

stroma: fluid within chloroplast, site of Calvin cycle

thylakoid membrane: membrane in stroma, site of light-dependent reactions, stack is called granum

lumen: inside of thylakoid, accumulates H+ ions, very acidic

Light Dependent Reactions

thylakoid membrane

Provide ATP and NADPH for light-independent reactions

noncyclic and cyclic phosphorylation

photosystems (I and II)

protein complexes containing pigments like chlorophyll and carotenoids

absorb blue and red light, reflex green light

has porphyrin ring with magnesium in the center

reaction center: pair of chlorophyl that converts light to chemical energy

Non-cyclic Photophosphorylation

1) photolysis

2) e- reach reaction center and get excited by light energy, passed to acceptor, and enter the first electron transport chain. Multiple ATP synthase molecules are creating ATP throughout the membrane

3) e- go through redox reactions in first ETC, protons pumped from stroma to lumen

4)e- reach PSI and re-energize, pass to another acceptor and enter second ETC

5) second ETC leads to NADP+ reductase. NADPH reduced

6) protons use ATP synthase to produce ATP

photolysis

light energy used to split water molecule. e- are passed to PSII, and H+ accumulate in lumen

Cyclic photophosphorylation

PSI passes e- back to first ETC making a loop

produces ATP but not NADPH

Light-Independent Reactions

Calvin cycle in stroma

Carbon fixation: CO2 and RuBP combined by enzyme RuBisCo to form PGA

Reduction: PGA is phosphorylated by ATP and reduced by NADPH to form G3P

Regeneration: most G3P is converted back to RuBP

Carbohydrate synthesis: some G3P is used to make glucose molecules

Photorespiration

RuBisCo reacts with O2 to produce PGA and phosphoglycerate molecule

this molecule most go through peroxisome and mitochondria to convert to PGA, wastes energy

Hot and Dry conditions lead to stromata closure which accumulates O2

C2 photosynthesis

C4 photosynthesis

bundle sheath cells used for spacial isolation

Pep converted to oxaloacetate converted to malate

malate transfered to budle sheath cells that are located deeper in cell where O2 levels are low

CAM photosynthesis

Crassulacean Acid Metabolism

temporal isolation

stromata cloed during day to prevent transpiration but open at night when CO2 is converted to malate and stored in vacuoles

during day, malate decarboxylated

Batesian Mimicry

non-harmful animals mimic colors of harmful animals

Mullerian Mimicry

different poisonous species have similar appearances, making them more intimidating

diaphysis of long bone

shaft of long bone, made of compact bone

epiphysis

round end of long bone

metaphysis

widen “neck” portion of long bone

periosteum

outer membrane that covers the surface of all bones

medullar cavity

central cavity of the bone shaft, filled with yellow bone marrow and adipose tissue

Interphase Cell Cycle

G1, G0, S, G2

90% of a cells life

M Phase of cell cycle

actively dividing

karyokinesis

cytokinesis

Gap Phase 1, G1

preps for cell division, check for favorable conditions

G0 Phase

cell does normal functions but does not prepare for division

goes back to G1

Synthesis phase

cell replicates the genome and centrosome

Gap Phase 2, G2

Organelles replicate, DNA is assessed for errors, checks the mitosis-promoting factor

Eukaryotes M phase

mitosis plus meiosis, uses microtubule organizing centers

prokaryotes M phase

binary fission, genome replicates while cell division occurs

Pericentriolar material

Stimulates growth of microtubule nucleation, extension of spindle apparatus

polar microtubular organizing center

connect centrosomes and push to opposite sides of cell

astral microtubular organizing center

attach to cell membrane for orientation in cell

kinetochore microtubular organizing center

attach to kinetochore on chromosomes to pull them apart

Surface to volume cell cycle regulation

decrease in S/V ratio leads to cell division

genome to volume cell cycle regulation

decrease in g/v ratio leads to cell division

cell cycle check points

G1 restiction point

G2 genome and protein check

M checkpoint: microtubules connected to chromosomes properly

cyclin-dependent kinases

phosphorylate certain microtubules in order to signal cell cycle progression

activated by cyclin

anchorage dependence

cell likes to be anchored to an external surface before it replicates

density dependent inhibition

halt cell division when density of surrounding cells is too high

Mitosis

prophase

metaphase

anaphase (chromosome number doubled, chromatin number stays the same)

telophase

plant cells cytokinesis

split later than animal cells, form cell plates which form middle lamella

homologous chromosomes

two different copies of the same chromosome in a diploid organism

one from the paternal gene one from the maternal gene

gametes

sex cells, sperm and egg are haploid n=2

germ cells

undergo mitosis to form more diploid germ cells

undergo meiosis to form haploid gametes

Meiosis 1

separated homologous chromosomes

prophase 1: synapsis, chiasmata

metaphase 1

anaphase 1: chromosome number stays the same

telophase 1: two new daughter cells are haploid