Quiz 1 Flashcards by Sarah Hughes

Cell Theory

Cells are units of life; living organisms made up of cells, smallest unit of living organism, come from other cells (structure depends on matter, energy, organization, information

How well did you know this?

Not at all

Perfectly

Prokaryote

Doesn’t have nucleus, “simple” structure (bacteria, archaea)

How well did you know this?

Not at all

Perfectly

Eukaryote

Does have nucleus and membrane-bound organelles; “complex” structure (protists, plants, fungi, animals)

How well did you know this?

Not at all

Perfectly

General structure of bacterium

Nucleoid, chromosomes, cytoplasm, ribosomes, flagella, three coverings (glycocalyx that traps water, cell wall that offers structure, and plasma membrane that encloses it)

How well did you know this?

Not at all

Perfectly

Organelle

Intercelllular component that performs distinct function (membrane bound or no membrane)

How well did you know this?

Not at all

Perfectly

Genome

Genes; all DNA that you have, contains info used to make proteins

How well did you know this?

Not at all

Perfectly

Proteome

Made up of amino acids and are expressed forms of genes; can be structural or functional (all cells have full copy of genome but different proteomes

How well did you know this?

Not at all

Perfectly

Differences in proteomes between cells can be due to:

Proteins are unique to certain cell types, proteins can be expressed at different levels, differential splicing, post-translational modifications

How well did you know this?

Not at all

Perfectly

Plasma membrane

Enclosed cell; interface between cell and its environment (selectively permeable, maintains differences between environments outside vs. inside cell

Structure: lipid bilayer, membrane proteins

Functions: membrane transport, cell signaling, cell adhesion

How well did you know this?

Not at all

Perfectly

Cell coat

Covers plasma membrane, composed of sugars, protects cell

How well did you know this?

Not at all

Perfectly

Cytoplasm

Everything inside cell minus nucleus

How well did you know this?

Not at all

Perfectly

Cytosol

Liquid part of cytoplasm (50% volume)

Functions: metabolism, signaling pathways

How well did you know this?

Not at all

Perfectly

Cytoskeleton

Network of filaments (protein fibers) in cell; motor proteins

Structure: fibers are made of proteins (actin filaments, microrubules, and intermediate filaments)

Functions: cell organization, shape, movement, strength

How well did you know this?

Not at all

Perfectly

Ribosomes

Located in cytosol and membranes

Structure: two subunits made of protein and RNA

Function: translates proteins by means of genetic code stored in mRNA

How well did you know this?

Not at all

Perfectly

Proteasome

Not membrane bound, made of proteins; digests proteins–recycle!

How well did you know this?

Not at all

Perfectly

Centrioles and centrisome

Centrioles composed of protein, compounds if centrosome; where microtubules eminate from

How well did you know this?

Not at all

Perfectly

Nucleus

Structure: nuclear envelope (inner membrane, perinuculeur space, and outermembrane), nucleur pores

Functions: stores and expresses genetic info

How well did you know this?

Not at all

Perfectly

Nucleolus

Structure: no membrane, large aggregate of macromolecules in nucleus

Function: ribosome factory

How well did you know this?

Not at all

Perfectly

Endoplasmic reticulum

Rough ER contains ribosomes and smooth ER doesn’t

Structure: single membrane with ER lumen inside

Function: RER is where proteins are synthesized and processed then transported in vesicles to GA, SER detoxifies, stores Ca, and synthesizes lipids

How well did you know this?

Not at all

Perfectly

Golgi apparatus

Structure: stack of 4-6 flat membrane enclosed compartments called cisterna; three distinct compartments (cis golgi network, cis/medial/trans cisterna) and trans golgi network

Functions: major site of carb synthesis; processing and pack and tag

How well did you know this?

Not at all

Perfectly

Lysosome

Structure: single membrane, contains acid hydrolases

Functions: breakdown of macromolecules to components

How well did you know this?

Not at all

Perfectly

Mitochondrion

Endosymbiotic hypothesis: used to be bacteria then engulfed by primitive eukaryotic cell

Structure: outer membrane, intermembrane space, inner membrane with folds called cristae; mitochondrial matrix

Functions: produces ATP by cellular respiration, apoptosis

How well did you know this?

Not at all

Perfectly

Peroxisomes

Structure: small, single membrane, matrix

Function: oxidate chemical reactions, breakdown fatty acids, endogeneticd source of DNA damage

Four characteristics of genetic materi

Replicate, store information, express information, allow variation by mutation

Central dogma of molecular genetics

DNA -> RNA -> protein

Fredrich Miescher

(1868) first one to discover DNA, called it nuclein

Phoebus A. Levene

(1910) DNA contains four different components (A, T, C, and G)

Tetranucleotide hypothesis

One unit contains all four linked nucleotides, ATCG, over and over identically/equally

Edwin Chagraff

(1940s) showed all four components are not present in equal amounts in DNA (A=T, G=C)

Griffith experiment

Experiment with pneumonia in which some harmless strands IIR and some heat-killed virulent strands IIIS were injected into a mouse and it DIED and live IIIS cells were found Griffith called it transformation but didn't know it was DNA

Avery MacLeod and McCarty experiment

Showed substance was DNA by ruling out proteins and RNA by rupturong heat killed bad guys and filtering out everything but the DNA, RNA, and proteins, THEN add no treatment, protease, ribonuclease., and deoxyribonuclease to different tubes and add living IIR bacteria to see which one still made them IIIS

Henry-Chase experiment

Additional evidence that DNA is genetic material by using T2 bacteriophages (50% protein 50% DNA) with either radioactive sulfur (in protein) or phosphorus (in DNA) to inject e coli bacteria and whichever one appeared was the substance that was genetic code

Protoplasts

Bacteria with outer cover removed

Indirect evidence that DNA is genetic material

Distribution of DNA (found only in nucleus rather than everywhere like protein) and mutagenesis (UV light produces mutations at 260nm; DNA absorbs at 260nm while protein absorbs at 280nm)

Direct evidence

Recombinant DNA technology (genetic engineering)

Three components of a nucleotide

Sugar, nitrogenous base, phosphate group

Pentose sugar in DNA and RNA respectively

Deoxyribose (H on C2) and ribose (OH on C2)

C1 is the carbon on a pentose sugar to which

the nitrogenous base is bonded

C3 is the carbon to which

OH is bonded

C5 is the carbon to which

The phosphate group is bonded

Two classes of nitrogenous bases

Prunes (adenine and guanine) and pyrimidines (cytosine, thymine-DNA ONLY, and uracil-RNA ONLY)

Similarities and differences between nucleotides in DNA

All contain same type of sugar and phosphate group, but can contain four different bases

Nucleotide names based on number of phosphate groups

NMP (one phosphate) NDP (two) NTP (three)

A nucleoside is composed of

A base and a sugar

Nucleotides are linked together by means of a

Phosphodiester bond

A chain of nucleotides has

A 5' and a 3' end; oligonucleotide chains have fewer than 15-30; polynucleotides have more

What did Changraff show about DNA compositon?

A=T and C=G, so ex: 15% A means 15% T and 35% C and 35% G

Rosalind Franklin

Found DNA was helix

Watson and Crick

Found DNA wad a double-stranded, right-handed helix that runs in an anti-parallel fashion with major and minor grooves

Complementary nature of base pairs

Any base pair is composed of a purine and a pyramidine to ensure diameter is always 20 Å (A bonds with T which is a two hydrogen bond and C bonds with G which is a three hydrogen bond)

Sugar-phosphate backbone of a DNA molecule

Sugars and phosphates face outside of helix, wrapping outside of DNA

How is DNA is a stable structure

it has many base pairs so many hydrogen bonds and because of hydrophobic and hydrophilic interactions

A-DNA and B-DNA are both

right handed (only Z-DNA is lefthanded)

Differences between RNA and DNA

The sugar is ribose in RNA (rather than deoxyribose), the pyrimidine base is U instead of T, and RNA is single stranded; a secondary structure in RNA is a region that is double stranded because of base pairing

Three major classes of RNA

messenger RNA (mRNA, 5% of RNA in e coli), ribosomal RNA (rRNA, 80% in e coli), and transfer RNA (tRNA, 15% in e coli)