General Biology Test 1

nervous system

circuits of neurons and support cells

neuronal plasticity

ability of nervous system to be modified after birth

memory

anatomical and physiological event occurring at synapses (depends on neuronal plasticity and activity)

short term memory (stm)

short time and limited capacity (released and replaced if unused)

long term memory (ltm)

when info needs retaining, infinite time and capacity (can’t use directly so retrieve to stm)

learning

use knowledge and experiences to decrease likelihood of negative outcome

long term potentiation (ltp)

long term increase in strength of synaptic transmission

encoding

low level to high level memory

retrieval

high level to low level memory

ltp is facilitated by?

organization, association, chunking, and activity

characteristics of stm

seconds to minutes, 5-9 ítems, immediate access, retained by sensory info, hippocampus, released if not used, weaker and less neuronal plasticity and synapses

characteristics of ltm

infinite time, infinite capacity, access by transfer to stm, retained by repeated use, cerebral cortex, not release if not used, stronger and more neuronal plasticity no synapses

sequence memory formation

stimulus —> sensory memory storage —> short term memory —> long term memory

evolution

big unifying idea, all living organisms are modified descendants of common ancestors

emergent properties

the result from arrangement and interaction of parts within a system, only exist because of arrangement (whole > sum of parts)

sequence levels of biological organization

(largest) biosphere, ecosystems, communities, populations, organisms, organs, tissues, cells, organelles, molecules (smallest)

method of inquiry

find natural explanations for natural phenomena, limited to observable and measurable things

hypothesis

testable proposed explanation for observation based on observable data (light does not work because the bulb is dead)

prediction

expected outcome when you test a hypothesis (if the bulb is dead it will work when replaced)

theory

broad explanation with significant support, leads to new hypotheses and accurate predictions (earth revolves around the sun)

law

statement of what always occurs under certain circumstances (law of conservation of energy)

sequence scientific process

background info —> generate hypothesis —> make predictions —> experiments and observations —> evaluate accuracy of predictions —> (incorrect —> repeat experiments and observations, revise hypothesis, revise predictions) (correct —> repeat and verify —> ask a new question)

chemical bonds

how atoms share electrons (react for full valence shell)

electronegativity

high strength in pulling electrons toward itself

high electronegative atoms?

oxygen and nitrogen

low electronegative atoms?

carbon and hydrogen

covalent bond

atoms are sharing electrons, stronger in biology

nonpolar covalent bond

electrons shared equally between atoms, strong in water, close or equal electronegativity, O2 and CH4

polar covalent bond

unequal electronegativity, unequal sharing (cause partial + or - charges), average strength in water, H2O

ionic bond

highly unequal electronegativity, electrons lost and gained, weaker in biology (dissolve in water), NaCl

anion

negative, gained electron in ionic bond

cation

positive, lost electron in ionic bond

van der waals reaction

short, weak, temporary, hydrogen bonds, nonpolar and electrically neutral molecules, regions of weak charges, strong in numbers only, short distance

sequence strength of types of bonds

ionic < hydrogen < covalent

hydrogen bonds

H bonds to electronegative atom (polar covalent) then h bond is between those 2 molecules (main one is between multiple water molecules)

atoms

made of protons, neutrons, and electrons

electron

charge of -1

potential energy

energy that a material possesses due to location (or structure), can be used to do work/cause change

what happens when electrons move shells?

absorb E to move to higher shell, release E when falling to a lower shell

valence shell

outermost shell and valence electrons occupy it

molecule

compound of 2 or more atoms held together by chemical bonds, have emergent properties

what are emergent properties of water?

cohesion (attraction between water molecules), adhesion (attraction between water molecules and other substances), moderates temperature (high specific heat), expands when frozen (freeze from the top), universal solvent (anything polar will dissolve, all hydrophilic will dissolve), forms H bonds for cohesion and adhesion

energy with bonds?

forming —> store E, breaking —> release E

hydrocarbon

organic molecules of only C and H, nonpolar, uncharged, hydrophobic

functional groups

key to molecular function

carbonyl

-OH, polar, hydrophilic, neutral, single bonds, origin —> alcohol

hydroxyl

>C=O, polar, hydrophilic, neutral, single bonds, origin —> sugar

carboxyl

-COOH, polar, hydrophilic, acidic, double bonds, origin —> amino acid and fatty acid

amino

-NH2, polar, hydrophilic, basic, single bonds, origin —> amino acids

phosphate

-PO4H2, polar, hydrophilic, acidic, single bonds, origin —> ATP, nucleic acid, and phospholipid

methyl

-CH3, nonpolar, hydrophobic, neutral, single bonds, origin —> DNA

carbohydrates

monosaccharides, simple sugars, polysaccharide polymer, glycocidic linkage, fuel structure

lipid

glycerol, Esther linkage fat, phospholipid, steroid, no polymer, 1 glycerol + 3 fatty acids, storage, signaling, structure

protein

amino acid, peptide bonds, amino group + central C + side chain + carboxyl group, all functions except heredity

nucleic acid

polymer, DNA, RNA

macromolecules

thousands of atoms (not all macromolecules are polymers)

polymers

linked monomers (all are macromolecules)

monomers

identical or similar building blocks

monosaccharides

simple sugars, 3-6C, glucose, repeating units

polysaccharides

100s to 1000s of monosaccharides, connected by glycosidic linkage, storage and structure of cells, starch, cellulose

fats

energy, synthesis by dehydration —> Esther linkage (builds lipids), glycerol —> 3C alcohol (3-OH) (glycerol + fatty acid)

phospholipids

storage, membrane, glycerol + 2 fatty acids + phosphate, amphipathic, fatty acid tail, phosphate head

amphipathic

hydrophilic and hydrophobic regions

steroids

signaling, 3 6-C rings + 1 5-C ring, differ in functional groups, cholesterol

peptide bonds

amino acid joined by peptide bond between carboxyl and amino acids

polypeptide

many 100s of amino acids joined linear by peptide bonds, not yet a protein requires shape

sequence polymerizaton

primary (polypeptide) —> secondary (local folding of polypeptide, hydrogen bonds) —> tertiary (3D folds, long distance, R group side chain, any bonds, can be finished here) —> quaternary (same as tertiary with 2 or more polypeptides fold together, hemoglobin)

denatured —> unfolded proteins, lost function, large structure, interactions disrupted

organic compounds

C bonded to C or H

chemistry of life

study of carbon compounds

sequence abiogenesis

abiotic synthesis of monomers —> formation of organic molecules —> formation of protocells —> appearance of self-replication

abiotic synthesis of monomers

requirements: E source, low/no free O2, chemical components, lots of time

hypothesis: Oparin-Haldane hypothesis vs. Iron Sulfur hypothesis

formation of organic molecules

facilitated by metal ions, form on clay/rock for minerals (catalyze polymerization), polypeptides, polysaccharides, polynucleotides, vesicles

formation of protocells

abiotically produced organic molecules, unique internal chemical environment, osmotic swelling, vesicles with organic material in it, organic polymers/macromolecules

appearance of self-replication

genetic info stored in DNA, transmitted by RNA, translated by protein, RNA Peptide World hypothesis

RNA Peptide World hypothesis

use RNA not DNA to store genetic info because it can work as an enzyme

Optaron-Haldane hypothesis

life formed in shallow water, near the surface

Iron-Sulfur hypothesis

life formed in deep sea vents, not near surface, most promising

vesicle

fluid filled compartment surrounded by membrane like structure, lipid filled, spontaneously forms lipids in water, small, temporary, transport

protocells

aggregates of abiotic ally produced organic molecules, electrical potential across surface, absorb materials, unique internal chemical environment, divide if significantly large or unstable

ribozymes

RNA enzymes (can catalyze polymerization)

sequence life on earth

first cells: prokaryotes, anaerobic, heterotrophic —>

autotrophy: use E from sun to make own food —>

oxygen revolution: rise in O2 from photosynthesis, killed most organisms —>

eukaryotes: cells with membrane bound nucleus and organelles, generated with endosymbiosis, ~1.8 bya

endosymbiosis

cell eats another that becomes part of the one who ate it

cell

smallest unit that carries out all activities associated with life

prokaryotes

mainly bacteria, plasma membrane, ~4 bya, nucleiod region, no nucleus, cytoplasm, 1-10 um, DNA, ribosomes, simple cells, no membrane bound organelles, binary fission, unicellular, not specialized, no aerobic respiration, no mitochondria

eukaryote

plasma membrane, ~1.8 bya, nucleus, cytoplasm, 10-100 um, DNA, ribosomes, complex cell, membrane bound organelles, meiosis, multicellular, specialized, aerobic respiration (mitochondria)

sequence protein processing

ribosome catalyzes peptide bonds —> R groups on amino acids interact —> vesicle exits ER —> protein modified in Golgi apparatus —> exocytosis

cell components

nucleus, nuclear envelope, nucleolus, ribosomes, endomembrane system, membrane, plasma membrane, endoplasmic reticulum, Golgi apparatus, vacuole, lysosome

nucleus

contains most DNA, most visible feature

nuclear envelope

origin by endosymbiosis, double membrane separate nucleoplasm from cytoplasm, regulated passage, protein complexes

mitochondria

origin by endosymbiosis, aerobic respiration for eukaryotes, make ATP, parts: outer membrane, intermembrane, inner membrane, matrix,

chloroplast

photosynthesis, parts: outer membrane, intermembrane, inner membrane, strong, thylakoid membrane, thylakoid space

ribosomes

not membrane bound, protein synthesis, made of RNA and protein, in cytoplasm and associated with ER

endomembrane system

internal membrane system, divides cell into components, lipid bilayer (closed), parts: ER, rough ER, smooth ER, Golgi apparatus, vacuoles, lysosomes

endoplasmic reticulum (ER)

internal membrane complex, 1 contiguous lumen, connected to outer membrane of nuclear envelope

rough ER

ribosomes attached to outer surface, proteins made and transported to lumen

smooth ER

lipid synthesis, metabolism, very few except in specific cells

Golgi apparatus

many membranes, no contiguous lumen, modify and transport proteins, use vesicles for movement

vacuoles

large vesicles, large and persistent, many functions: food, contractile, storage

lysosome

compartments containing hydrolytic or digestive enzymes, made in rough ER, processed in Golgi apparatus, inactive until food is present

membrane communication

direct communication (1 compartment, go anywhere inside) vesicular transport (transfer of membrane segments)