IB HL BIO UNIT ONE

Spontaneous formation of vesicles

Process where fatty acids self-assemble into spherical structures called vesicles in aqueous environments

Last universal common ancestor (LUCA)

unicellular, autotrophic, lived in hypothermal vents, around 2.5-3.5 billion years ago

evidence- universal genetic code & conserved genes in all organisms

reproduction

one of the 8 processes of life

all living things make new, similar living things

sexual: 2 sources of genetic information, genetic diversity

asexual: 1 source of genetic information, makes an exact copy

homeostasis

one of the 8 processes of life

the ability to maintain a constant internal environment

ex: sweating, constant internal temperature, water/salt/pH/sugar balances

nutrition

one of the 8 processes of life

the process of taking in food and converting it into energy and other vital nutrients required for life

response to environment

one of the 8 processes of life

organisms notice and react to stimuli (changes in environment), often leads to movement

movement

one of the 8 processes of life

often occurs as a reaction to stimuli (changes in environment)

growth

one of the 8 processes of life

must have a pattern of growth (maturity) and development (develop to do different jobs for the organism)

the 8 processes of life

homeostasis

response to environment

movement

reproduction

growth

nutrition

metabolism

excretion

ribonucleic acid

aka RNA

first genetic material

has catalytic properties

protocells

formed spontaneously & in an aqueous environment

proto- = first, origional

less complex than current cells

viruses

posses:

• DNA

• adapt/evole

• response to environment

lack:

• growth

• reproduction

• homeostasis

• metabolism

• energy use

• movement

• cells (no membrane)

organic molecules

contain carbon, hydrocarbons

miller-urey experiment

proved that non-living synthesis of organic molecules was possible in the assumed conditions of early earth

organic compounds can be formed from inorganic precursor molecules

cell theory

1. all living things are made of one or more cells

2. cells are the basic unit of life

3. all cells come from pre-existing cells and multiply by division

geotropism/gravitropism

roots grow down in response to gravity

stimuli

change in the environment that results in some sort of response

phototropism

stem grows towards the sunlight

metabolism

all chemical reactions that occur in a cell

excretion

one of the 8 processes of life

getting rid of waste caused by metabolic reactions

prokaryotes

earliest, most primitive cells

unicellular organisms

smaller

70S ribosomes (free in cytoplasm)

cell wall, maintains shape

plasma membrane

naked DNA in a loop (nucleoid)

plasmid, horizontal gene transfer

eukaryotes

larger, more complex

multi & unicellular organisms

membrane-bound organelles (aka compartmentalization)

80S ribosomes

plasma membrane

nucleus, DNA

smooth & rough endoplasmic reticulums

golgi apparatus, processes and packages proteins

vesicle, small sac, transports and releases

ribosomes

responsible for protein synthesis

found in both prokaryotic (70S) and eukaryotic (80S) cells

can be free-floating in the cytoplasm or attached to the endoplasmic reticulum

translate genetic information from DNA into functional proteins

cell membrane

Thin, flexible barrier surrounding all cells

Controls movement of substances in and out of the cell

Maintains cell's shape and integrity

cell wall

found in prokaryotes, plant (composed of cellulose), and fungi (composed of chitin) cells

provides structural support

keeps shape of cell

cytoplasm

where chemical reactions happen

found in all cells

mitochondria

“powerhouse of the cell”

releases energy into cell

nucleus

controls cell’s activities

stores DNA

found in eukaryotic cells

early earth conditions

atmosphere lacked free O2

no ozone layer, more UV light reached earth’s surface

CO2 and CH4 (in the atmosphere) = greenhouse gases, trap heat, higher temperatures

aseptate fungal hyphae

type of fungi cell

very large, multi-nucleated

cytoplasm is continuous along the hyphae, no end cell wall or membrane

striated skeletal muscle

type of animal cell

very long (300mm)

single plasma membrane, multi-nucleated

red blood cells

type of animal cell

no nucleus, no DNA (allows for more hemoglobin storage)

phloem sieve tube cells

type of plant cell

“plumbing of a plant”

no nucleus, few organelles

rely on local companion cells for survival

endosymbiotic theory

eukaryotic cells evolved from prokaryotic cells

mitochondria(1st) and chloroplasts(2nd) in eukaryotic cells are thought to have once been prokaryotic cells that were engulfed and established symbiotic relationships

mitochondria and chloroplasts have a double membrane, 70S ribosomes, circular DNA, reproduce independently (similar to binary fission)

vacuoles

mainly in plant and fungi cells (small and temporary in animal cells)

storage systems

cells

the smallest things considered fully alive

make up all living things

unicellular organism

made of one cell

can be prokaryotic or eukaryotic

multicellular organism

made of more than one cell

eukaryotic

anabolic pathways

synthesis (building) of complex molecules from simpler molecules

condensation reaction, dehydration synthesis

2 monomers join as they lose a water molecule

catabolic pathways

breaking down of complex molecules into simpler ones

hydrolysis (hydro- water, -lysis split) reaction that disassembles polymers to create monomers

inserting a water molecule to break up larger molecules

nucleotide

monomer of nucleic acids

polynucleotide

polymer of nucleic acids

phosphodiester bonds

holds together monomers in nucleic acid

nucleic acids

store, access, and transmit genetic information

DNA & RNA

nucleotide parts

• a phosphate group

• 5 carbon (pentose) sugar

• nitrogenous base

nitrogenous bases

DNA- thymine

both- adenine, guanine, cytosine

RNA- uracil

purines (nitrogenous bases)

2 rings

guanine & adenine

always bond with pyrimidines

pyrimidines (nitrogenous bases)

1 ring

cytosine, thymine, & uracil

always bond with purines

DNA

nitrogenous bases - thymine, cytosine, adenine, & guanine

pentose sugar - deoxyribose sugar

double stranded (helix)

stores genetic information

phosphodiester bonds

RNA

nitrogenous bases - uracil, cytosine, adenine, & guanine

pentose sugar - ribose sugar

single stranded

acesses genetic information

phosphodiester bonds

antiparallel

same distance apart and will not intersect BUT face different directions

hydrogen bonds

holds together the complementary base pairs in DNA

weak attraction between a slightly positive hydrogen and a slightly negative atom

DNA base pairing rule

A pairs w/ T

G pairs w/ C

strands must be parallel, distance between must be uniform

purine & pyrimidine = width consistent with X-ray data

bacteriophage

virus that infects bacteria by injecting genetic material

contains protein shell and nucleic acid core

Hershey and Chase experiment (1952)

tested to see if proteins or DNA carried genetic material

proteins - 20 amino acids, would be more genetic diversity

DNA - only 4 bases, they thought it was unlikely to be genetic material

put radioactive sulfur in the protein shell and radioactive phosphorus in the DNA

found radioactive phosphorus in the bacteria, DNA = genetic material

Chargaff experiment

looked at proportions of the different bases in DNA (A, T, G, C) of different species

different species have different proportions of each base

A = T, G = C, A + G = C + T

Rosalind Franklin (experiment)

wanted to find structure of DNA

used x-ray crystallography to take pictures

DNA = double helix

Watson and Crick (experiment)

credited with double helix model of DNA (franklin actually discovered it)

lead to base pairing rules