Cell Bio Chapters 1-4

what is cytology

study of cells

what is a cell

basic, microscopic structural and functional unit of any living organism

what are the parameters of microscopy

magnification, resolution, and contrast

what is magnification in microscopy

the ratio of the image size to the real size

what is resolution in microscopy

the clarity of the image

what is contrast in microscopy

the difference in brightness

what are the characteristics of light microscopy

a wide range of magnifications, needs a visible light source, samples can be alive or fixed, samples can be transparent, sectioned, or stained

what are the characteristics of fluorescent microscopy

two sets of filters for excitation and emission wavelengths, excitation filter filters light before it reaches the specimen so only applicable ones pass through, needs a visible or UV light source, samples can be alive or fixed, samples can have fluorescent proteins or dyes

which is higher, excitation or emission energy

excitation energy is always higher

what are the characteristics of confocal fluorescent microscopy

scans small sections of the sample with a laser beam, generates a sharper image

what are the characteristics of transmission electron microscopy (TEM)

shoots electrons, thin specimen stained w/ electron-dense heavy metal is placed in vacuum, electrons locally absorbed or scattered, magnification million-fold, no live specimen

what are the characteristics of scanning electron microscopy (SEM)

specimen coated w/ film of heavy metal, electrons focused by magnetic coils, creates images of 3d objects

when and by who were the first observations of microorganisms with a microscope

protozoa in 1674, bacteria in 1683, observed by Antonie van Leeuwenhoek

what is the central dogma

process by which there is flow of information from DNA to RNA to protein (replication, transcription, translation)

what is replication

DNA synthesis

what is transcription

RNA synthesis

what is translation

protein synthesis

what are the three domains of life

bacteria, archaea, and eukaryotes

what are the characteristics of bacteria

prokaryotic, peptidoglycon cell wall

what are the characteristics of archaea

prokaryotic, cell wall does not contain peptidoglycan, suited for harsh environments

what are the organelles in a eukaryotic cell

nucleus, nucleolus, mitochondria, golgi apparatus, endoplasmic reticulum, ribosome, peroxisome, vesicles, endosomes, cytoplasm, cytosol, cytoskeleton, cell membrane, centrioles, ANIMAL ONLY: lysosome, PLANTS ONLY: chloroplast, cell wall, lyctic vacuole

nucleus

control of cellular activity through regulation of gene expression

mitochondria

POWERHOUSE OF THE CELL, generation of energy in the form of ATP via oxidative phosphorylation

smooth endoplasmic reticulum

no ribosomes, lipid synthesis, steroid hormone synthesis, detoxification, storage of calcium ions

rough endoplasmic reticulum

protein synthesis, translocation, folding, glycosylastion, antigen processing

golgi apparatus

protein modification through glycosylation, completion of glycolipid and sphingomyelin synthesis

endosomes

sorting of proteins between endocytic and exocytic traffic, sorting of receptors and ligands, signaling from ER to golgi body

lysosomes

degradation, autophagy/turnover of organelles, antigen processing

what is apoptosis & autophagy

apoptosis: programmed cell death

autophagy: once the cell dies, the parts can be recycled by fusing with the lysosome and breaking everything down into components

peroxisomes

synthesis and degradation of hydrogen peroxide, oxidation of fatty acids, photorespiration in plants

cytoskeleton

make the cell structure and allow movement

cytoplasm

cellular content inside the plasma membrane and outside the nucleus

cytosol

content of the cytoplasm, including membrane-bound organelles

plasma membrane

phosopholipid bilayer; serves as a barrier, provides structure, controls transport, important for cell signaling and recognition

nucleolus

place of ribosomal assembly; granular component does pre ribosome assembly, fibrillar center does rRNA transcription, dense fibrillar component does pre-rRNA processing

centrioles

spindle formation, flagellum and cilium formation

what organelles are present only in animal cells?

lysosome and centrioles

what organelles are present only in plant cells?

lyctic vacuole, cell wall, and chloroplast

chloroplast

performs photosynthesis

the lyctic vacuole performs the same function in plants as the ___ does in animals

lysosome

what eukaryotic organelles have a single membrane?

lysosome, endoplasmic reticulum, golgi body

what eukaryotic organelles have a double membrane?

chloroplast, nucleus, and mitochondria

eukaryotic cell evolution

compartmentalization → acquisition and formation of specialized organelles

which organelle originated from a primordial symbiotic relationship with archaea?

mitochondria

what is the definition of a mole

one mole of a substance is the number of grams that is numerically equal to the atomic/molecular mass

Avogadro’s constant

6.02214076 × 10²³ = 1 mol

atoms are (more, less) ____ stable when their valence shell contains the maximum number of electrons

more

what is the maximum number of valence electrons

2 in the innermost shell, 8 for other shells

covalent bonds

electrons sharing between atoms

organic molecules almost always form what kind of bonds with each other?

covalent

electronegativity

the tendency of an atom in a molecule to attract the shared pair of electrons towards itself

what does an atom’s electronegativity depend on?

its atomic number and the distance between its valence electrons and the charged nuclei

atomic number

number of protons

atomic mass

number of protons and neutrons

in which atoms is electronegativity the highest?

atoms that are closer to a stable state (Exception: hydrogen)

If the electronegativity difference between the atoms is LESS THAN 0.4, the bond is considered ___

polar

If the electronegativity difference between the atoms is BETWEEN 0.4 AND 1.6, the bond is considered ___

nonpolar

If the electronegativity difference between the atoms is GREATER THAN 1.6, the bond is considered ___

ionic, not covalent

noncovalent hydrogen bonds

electrical attraction between oppositely partially charged atoms from two different molecules

dipole-dipole attraction

occurs between hydrogen and a highly electronegative atom

ionic bonds

the electrostatic attraction between oppositely charged ions

van der waals attractions/forces

nonspecific interactions caused by fluctuations in the distribution of electrons in every atom; transient molecular bonds when two atoms get in close proximity

list the bonds strongest to weakest

covalent, ionic, hydrogen, van der waals

intermolecular bonds include:

hydrogen, dipole-dipole, van der waals

intramolecular bonds include:

covalent, ionic

organic molecules

molecules made of carbon and hydrogen (can include other elements, frequently O)

types of organic molecules important for cell function

carbohydrates, lipids, peptides/proteins, nucleic acids

macromolecules

the largest, most abundant molecules in cells

what are the building blocks of carbohydrates

mono/disaccharides, sugars

what are the building blocks of nucleic acids

nucleotides

what are the building blocks of lipids

fatty acids

what are the building blocks of proteins

amino acids

replication is the process of…

dna synthesis

transcription is the process of…

RNA synthesis

translation is the process of…

protein synthesis

what is the order of the central dogma

replication, transcription, translation

types of RNA

messenger RNA, transfer RNA, ribosomal RNA

function of mRNA

transcribes genetic code

function of tRNA

translates genetic code

function of rRNA

used in the structure of genetic code

nucleotides consist of three parts:

a nitrogenic base, a 5-carbon sugar (pentose), and one or more phosphate groups

pentose used in RNA

β-D-ribose

type of pentose used in DNA

β-D-2-deoxyribose

purines

adenine and guanine

pyrimidines

uracil, cytosine, thymine

which nucleotide base is only used in RNA

uracil

phosphate is joined to the __ carbon in a nucleotide

5’ hydroxyl

the phosphate makes the nucleotide ___ (positively, negatively) charged

negatively

what kind of bonds join nucleotides together

phosphodiester bonds

where are the bonds in nucleotides formed

between the 5’ carbon of one nucleotide and the 3’ carbon of another

DNA and RNA are synthesized in what direction

5’→ 3’

base pairs in dna are connected by what kind of bonds?

hydrogen