BIOLOGY CHEAT SHEETS

ionic bond

transfer of e^- from one atom to another atom of very different electronegativity

covalent bond

sharing of e^- between atoms of similar electronegatives

nonpolar covalent bonds

equal e^- sharing

polar covalent bonds

unequal e^- sharing, forms dipole

dehydration reaction

links monomers to form polymers, forming H2O in the process

hydrolysis

uses H2O to break polymers into monomers

protein: linkage type

peptide bonds

protein primary structure

linear chain sequence of amino acids

determined by nucleotide sequence

protein secondary structure

alpha-helices/beta sheets

H-bonding between amino and carboxyl groups of adjacent amino acids

protein tertiary structure

3D shape

noncovalent interactions between R groups (disulfide bonds are covalent exceptions)

protein quaternary structure

3D shape consisting of 2+ separate polypeptide chains

carbohydrate linkage type

glycosidic

monosaccharide

glucose

fructose

sucrose

glucose + fructose

sucrose

polysaccharides

starch (alpha-glucose), glycogen (alpha-glucose), cellulose (beta-glucose), chitin (beta-glucose)

lipid linkage type

covalent carbon-carbon

3 types of lipids

triglycerides, phospholipids, steroids

triglyceride

glycerol + 3 fatty acids (saturated and unsaturated)

phospholipid

2 fatty acids + phosphate group attached to glycerol backbone

(polar head, nonpolar tail)

steriod

3 six-membered rings + 1 five-membered ring

porphyrin

4 joined pyrrole rings with a metal center atom

(non-lipid, but commonly associated with lipid membranes)

2 examples of porphyrins

chlorophyll, hemoglobin

nucleic acid linkage type

phosphodiester bond

DNA nucleotide

H attached to 2’ carbon of the sugar

RNA nucleotide

OH attached to sugar

In prokaryotes, the __________ region contains genetic material

nucleoid

___________ is the site of ribosome (rRNA) synthesis

nucleolus

___________ is the site of fatty acid catabolism

mitochondria

lysosome

functions in apoptosis, and break down of nutrients, bacteria, & cell debris

peroxisomes

common in the liver & kidney

breaks down substances and converts H2O2 by-product into H2O

cytoskeleton

maintain cell shape & movement

microtubules are composed of _________

tubulin

microtubule function

supports cell & motility

cilia

short hair-like extensions from cell for movement

flagella

longer thread-like extension from cell for movement

intermediate filaments are composed of _______

actin

microfilaments function

used for cell shape and division

contractile vacuole

expels excess water in hypotonic protists (amoeba, paramecium); absent in human cells

extracelllular matrix

provides mechanical support & helps connect adjacent cells

_______ is the single most abundant protein found in the extracellular matrix and the entire human body

collagen

traits of prokaryotes

1. no nucleus (nucleiod)

2. single, circular, naked, double-stranded DNA

3. ribosomes (50S + 30S = 70S)

4. bacteria (petidoglycan); archaea (polysaccharides) - many have sticky capsules on the cell wall

5. flagella are constructed from flagellin, not microtubules

ion channel protein

voltage-, ligand, or mechanically-gated

porins

less specific channel protein; pass iions and polar molecules

channel protein

passage through membrane for hydrophilic, polar, and charged substances

carrier protein

specific molecule can pass through after binding to protein and changing its shape

transport protein

use atp to transport materials across the membrane; includes active transport (Na+/K+ pump) and facilitated diffusion

active transport

uses ATP to transport against gradient

what solutes use active transport?

small ions, amino acids, monosaccharides

3 types of endocytosis

phagocytosis, pinocytosis, receptor-mediated endocytosis

phagocytosis

plasma membrane invaginates around undissolved material (solid), like bacteria

pinocytosis

plasma membrane invaginates around dissolved material (liquid)

receptor-mediated endocytosis

form of pnocytosis in which specific ligands bind to receptors

hypertonic

higher solute concentration

net water flow out of cell → shriveled

hypotonic

lower solute concentration

net water flow into cell → lysed

isotonic

equal solute concentration

no net water flow → normal cell

anchoring junction

includes desmosomes; connects cells together into sheets

tight junction

encircles each cell, producing a seal that prevents the passage of materials between cells; is characteristic of cells lining the digestive tract

gap junction

narrow tunnels between animal cells; allow passage of ions and small molecules

anabolic

small molecules assemble to form a larger molcule (usually decrease entropy)

catabolic

large molecules are broken into smaller molecules (usually increase entropy)

exergonic

free enery is released (spontaneous with -ΔG)

endergonic

free energy is absorbed (nonspontaneous with +ΔG)

enzymes act as catalysts by ________ the activation energy, which ______ the rate of reaction

lowering, increases

competitive inhibition can be overcome by ________ substrate concentration, Km ________, Vmax ________

increasing, increases, stays the same

in noncompetitive inhibition, the substrate can ____, but the inhibitor _________ reaction. Km ______, Vmax _______

stil bind, prevents, stays the same, decreases

Vmax

the maxiumum velocity of the reaction at peak substrate saturation

Michaelis Constant (Km)

the substrate concentration at which the rate of the reaction is half of the maximum velocity

Km ______ represents binding affinity

inversely

small Km = ______ substrate needed to reach Vmax = ________ binding affinity

less, higher

ATP is formed via __________, which creates ______ ____ triphosphate bond

phosphorylation, energy rich

ATP formation is an _______ reaction

endergonic

ATP is broken apart via _________, which releases ________ and _________

hydrolysis, energy, phosphate

ATP hydrolysis is an _________ reaction

exergonic

ATP stores energy generated from the _________ reactions in the electron transport chain, which can then be used to fuel ___________ reactions

exergonic, endergonic

Cellular Respiration Overview: ________ glucose via electron carriers to deposit their electrons in the ETC, fueling chemiosmosis to generate chemical energy for the cell in the form of ATP (__________)

oxidize, exergonic

glycolysis nets __ ATP and produces __ pyruvate

2, 2

T/F: glycolysis is universal to all organisms

true

Glycolysis is located in the __________

cytoplasm

substrate level phosphorylation glycolysis pathway (glucose → pyruvate)

glucose [hexokinase + ATP] → G6P [PGI] → F6P [phosphofructokinase + ATP] → F1,6Bp →→ pyruvate

2 important enzymes in glycolysis

hexokinase, phosphofructokinase (PFK)

hexokinase

• transforms glucose to G6P

• consumes 1 ATP

• phosphorylating glucose prevents it from leaving the cell

phosphofructokinase (PFK)

• adds second phosphate to F6P

• this step irreversibly commits the molecule to glycolysis

aerobic process: ______ required as final electron __________

oxygen, acceptor

aerobic respiration overall reaction

C6H12O6 + 6 O2 → 6 CO2 + 6 H20 + (36 to 38) ATP

pyruvate decarboxylation: pyruvate gets shuttled into the _____________ and then the pyruvate dehydrogenase complex (pdc) transforms pyruvate into __________

mitochondrial matrix, acetyl-CoA

acetyl-CoA enters the _____, where it is used to generate ____________

CAC, oxacloacetate

each cycle of CAC produces ____, ___, _____, and ____

CO2, ATP, FADH, NADH

krebs cycle is occurs in the ____________________

mitochondrial matrix

ETC major parts

oxidative phosphorylation, ATP synthase proton motive force and chemiosmosis

ETC occurs in _____________

inner mitochondrial membrane

oxidative phosphorylation

• electrons pass from electron carriers (NADH and FADH2) to other carrier proteins

• larger complexes pump H+ out, causing proton gradient to flow back into mitchondria

• ATP synthase produces ATP via proton motive force

____________ is the final electron accepter in ETC, which combines with H+ to form ______

oxygen, H2O

______ and ______ are oxidized by the ETC

NADH, FADH2

ATP synthase usees the H+ gradient for ___________

chemiosmosis

________ poisons the mitochondria, but affects _____________ not ________

cyanide, oxidative phosporylation, glycolysis

4 major steps of cellular respiration

glycolysis, pyruvate decarboxylation, citric acid cycle/krebs, etc

anaerobic respiration regenerates _________ from NADH for glycolysis to continue

oxidized NAD+

glycolysis can run _____________ (the absence of __________)

anaerobically, oxygen