Cells

when were the first microscopes created

1660

what did Robert Hooke observe

Cork, he drew and came up with the name for “cells”

who came up with the name cells and how did he do it

Robert Hooke, the dead cell walls he observed in his microscope reminded him of the cells of a monk’s monestary

who published the first cell biology textbook and what was it called

Robert Hooke, called micrographia

how much maginification did Robert Hooke’s microscope have

30x

who created the first 300x microscope

Antoine van leewenhoeke

what did antoine van leewenhoek create his microscope for

looking at fabric quality and thread count

when was the first electron microscope developed

1931

how do electron miscroscopes work

they focus a beam of electrons on or through a specimen

what are the 2 types of electron microscopes

Transmission electron microscopes (TEM) and Scanning Electron microscopes (SEM)

what does a TEM do

penetrates through a specimen to show organelles

what does an SEM do

scans surface of specimen to give a 3d image by scattering electrons on the surface

what colour are SEM and TEM images

black and white

what is electron microscopy magnification limited by

radiation damage

how is the radiation damage problem of electron microscopy fixed

cryo-EM

how does cryo-EM work

flash freezing molecules then bombarding them with electrons

what is cryo-em used for

visualizing individual molecules inside a cell

what are the 2 applications of fluorescence microscopy

1:Label a biomolecule inside a cell using antibodies and flrorochromes

2:fuse a green fluorescence protein to DNA and a cell will make a version of a specific protein that glows green

what kind of fluorescence microscopy is used to locate particular proteins in dead cells

antibodies and fluorochromes

what kind of fluorescence microscopy is used to track protein movement in the cell

fusing a green fluorescence protein to DNA

what did schleiden and schwann do

declared that:

-all organisms consist of one or more cells

-the cell is the basic unit of structure for all organisms

when did schleiden and schwaan make their declarations

1838-1839

what did virchow add in 1855 to schleiden and schwaan’s declarations

all cells arise by the division from pre-existing cells

who said that all cells aris eby the division of pre-existing cells

Virchow

what 2 groups are included in prokaryotes

Bacterial and Archaea

what evolved first, prokaryotes or eukaryotes

prokaryotes

what makes prokaryote cells different from eukaryote cells

-no membrane-bound nucleus

-circular, chromosomal DNA

-cytoplasm mostly devoid of membranous structures

-much smaller than eukaryotes

-extremely diverse

which cells have linear chromosomes

eukaryotes

do all cells have organelles

prokaryotic ones do not

what is the unit used to measure cells

micrometers

what is the unit used to measure cell structures

nanometers

how many nanometers in a micrometer

1000

what is the unit used to measure biomolecules

angstrom

how many angstrom in a nanometer

10

do cells work best with a larger or smaller volume

smaller volume, larger surface area

why do cells work best with a smaller volume and larger surface area

internal membrane capacity and diffusion rates within the cell

how have cells evolved to increase surface area without increasing volume

developing small projections called microvilli

what was the first protocell called and what does it stand for

LUCA, Last Universal Common ancestor

when was LUCA formed

1 billion years after earth formed

who recreated early earth in a closed system

urey and miller

what did urey and miller find in their experiment of early earth in a closed system

after a few weeks, amino acids and carbohydrates appeared

how long ago did mitochondria and chloroplasts form

1.25 billion years ago

what is the andosymbiont theory

a primitive eukaryotic cell engulfed a prokaryotic cell, which then had a symbiotic relationship and the prokaryotic cell eventually eveolved into an organelle.

how did mitochondria form according to the endosymbiont theory

if the prokaryote engulfed did aerobic respiration

how did chloroplasts form according to the endosymbiont theory

if the engulfed prokaryote did photosynthesis

what are the 4 large biomolecules in the cell

protein

nucleic acids

carbohydrates

lipids

which macromolecules are polymers

protein

nucleic acids

carbohydrates

not lipids

how are monomers assembled into polymers

through condensation reactions

how are polymers broken down into monomers

through hydrolisis reactions

what are used to catalyse hydrolysis

hydrolytic enzymes

what reactions occur in lysozomes

hydrolysis

what is the most important macromolecule in the cell in terms of functionality

proteins

what is the protein monomer

amino acids

what are the components of an amino acid

center carbon

carboxyl group

hydrogen atom

amino group

variable group (R group)

what are the 3 groups of amino acids

1:non-polar hydrophiobic

2:uncharged hydrophobic

3:charged hydrophilic

how do non-polar hydrophobic amino acids associate to each other

with van der waals forces

how do uncharged hydrophilic amino acids bond to other molecules

hydrogen bonds

how do charged hydrophilic amino acids bond to other molecules

ionic bonds

whata re the 3 special amino acids

-glycine

-cysteine

-proline

what is special about glycine

it is very small

can be polar or non-polar

what is special about cysteine

it will form covalent bonds with other cysteines called disulfide bonds

what is special about proline

it will form a disruptive kink in a polypeptide

how do amino acids bond together and what is it called

condensation reaction and the bond formed is called a peptide bond

Definition:Primary structure

amino acid sequence

Definition:Secondary structure

3d shape in localized area

what are the 2 big examples of protein secondary structure

alpha helix and beta-pleated sheets

Definition:Tertiary structure

proteins overall 3d shape

how is tertiary structure stabilized

in reactions between r groups

how would you predict a proteins 3d shape

you could do this just by knowing it’s primary structure

Deifnition: Protein domains

protein segments with distinct structures and predictable functions, each domain functions in a semi-independant manner

are domains dependant or independent in terms of function

each domain functions in a semi-independant manner

Definition: Quaternary structure

sometimes occurs when multiple proteins associate together to create one functional protein

Definition: prosthetic groups

large non-protein molecules embedded in a protein, that allow proteins to perform extra functions

what do prosthetic groups do

allow proteins to perform extra functions that they wouldn’t otherwise e able to do

what is a multi protein complex

rarely, multiple functional proteins will come together to make a multi-protein complex or molecular machine

what is an example of a multi-protein complex or molecular machine

ATP synthase

what did christian Anfinsen discover

that after being broken down, proteins can refold themselves

what is the other name for heat-shock proteins

molecular chaperones

what do molecular chaperones do

prevent inappropriate interactions between proteins, bind to amino acids such that they block other proteins from getting in the way

how does chaperonin work

it is barrel shapped and provides a space wherea new protein can fold properly without disturbances from other proteins

what are HSP70 and HSP40 examples of

molecular chaperones or heat-shock proteins

what are nucleic acid monomers called

nucleotides

what are the 3 parts of a nucleotide

nitrogenous base

5 carbon sugar

phosphate group

what are the 5 nitrogenous bases

thymine

guanine

cytosine

adenine

uracil

what are the 2 sugars that can be in a nucleotide

ribose or desoxyribose

how do nucleotides become nucleic acids

condensation reactions

what is the bond between nucleotides called

phosphodiester bond

what are the 2 things that are linked in a phosphodiester bond

phosphate of one nucleotide and sugar of another

how many strands of nucleotides does RNA exist as

1

how many strands of nucleotides does DNA exist as

2 strands running anti-parralel to each other that form a double helix

what gives DNA and RNA the ability to store and transmit information to the cell

the order of the nucleotides

what is the basics of how a protein is made

DNA is transcribed to make messenger RNA which is then translated in a ribosome and used as the instructions to assemble amino acids into proteins

what are carbohydrates composed of

carbon, hydrogen and oxygen

what is the molar ratio of carbohydrates

1:2:1 carbon, hydrogen, oxygen

what do carbohydrate names often end in

ose

what does the prefix glyco indicate

it means it has something to do with carbohydrates

what is the monomer of carbohydrates called

monosaccharides

what is the bond between 2 monosaccharides

glycosidic bond

what is a is a carbohydrate of 3-10 units called

oligosaccharide