Biology 212 #1

Bio212

What are the 5 fundamental characteristics of life?

cells, replication, evolution, information, energy

Who devised the microscope with 30x and who did 300x?

30x - Robert Hooke 300x - Anton Van Leeuwenhoek

What was Louis Pasteurs hypothesis for cells?

cells arise from cells and they don't arise by spontaneous generation

What and when was the first life on earth?

Prokaryotic cells (cyanobacteria) 3.6 million years ago

What are the smallest identifiable unit of matter?

atoms

What is an isotope?

atoms with different \# of neutrons

Who organized the periodic table?

Dmitri Mendeleev

How does the periodic table arrange horizontal (protons, energy shells, electronegativity)

increase protons, same \# energy shells, high electronegativity

How does the periodic table arrange vertical (valence e, energy shells, electronegativity)

same \# valence e, more energy shells, low electronegativity

What is an ion?

atom that has gained or lost electrons

What are the type of chemical bonds?

covalent, ionic, hydrogen

What bond shares unpaired electrons in valence shell, form for a more stable atom

covalent

what bond completely transfers electrons

ionic

What bond forms by the attraction between atoms or molecules with partial charges, break easily but strong overall

hydrogen

What bond is responsible for surface tension, cohesion and adhesion properties?

hydrogen

What is a substance that releases protons into a solution to increase the hydronium ion concentration, lower the pH

acids

what is a substance that take up free protons and decrease the proton concentration12 in a solution, increase the pH

bases

what do organic molecules consist of?

monomers and polymers

What are the 4 classes of organic molecules that all living organisms synthesize?

carbs, lipids, proteins, nucleic acids

How do amino groups act according to protons and does it act as a bases/acid?

attract protons and acts as a base

How do carboxyl groups act according to protons and does it act as a bases/acid?

drop protons and acts as an acid

How many amino acids are there?

20

Define : enzymes can speed up chemical rxns

catalysis

What are the 4 parts of a protein - amino acid?

hydrogen atom, amino group (NH2), carboxyl group (COOH) and R group (side chain)

What are the 4 folding steps of a protein?

primary, secondary, tertiary, quaternary

What is the primary structure of a protein?

amino acid sequence

What is the secondary structure of a protein?

interaction between functional group of side chain and hydrogen bonds

What does the secondary structure of a protein fold into?

a-helix (intrastand) and B-pleated sheet (interstrand)

What is the tertiary structure of a protein?

whole polypeptide chain folds in a 3D shape

What are the 5 important types of R-group interactions in a tertiary structure?

hydrogen bond, hydrophobic interactions, Van der Waals interactions, Ionic bonds, Disulfide bonds

What is the quaternary structure of a protein?

multiple polypeptide chains assemble into a single functional structure

What is the difference between a folded and unfolded protein?

folded is functional, active, and stable; unfolded is unable to function normally

what is it called when there are less than 50 amino acids, and when there is more than 50?

oligopeptide and polypeptide

What is the role of a plasma membrane?

separate a cells interior from environment and define organelles

Are lipids polar or nonpolar?

nonpolar

Are carbs polar or non polar?

polar

What are 3 major types of lipids?

fats (triglycerides), phospholipids, steroids

Whats the difference between saturated, unsaturated, and polyunsaturated

saturated (butter)- single bonds unsaturated (oil) - one or more double bonds polyunsaturated - many double bonds

What type of lipid is formed by dehydration reaction and made up of a hydrocarbon chain bonded to polar carboxyl group?

fats (triglycerides)

Do fats or carbs store more energy?

fats, nonpolar molecules store more energy

What type of lipid consists of 2 fatty acid chains linked to a phosphate chain?

phospholipids

Is a phospholipid hydrophilic, hydrophobic, or amphipathic?

amphipathic

What consists in a phospholipids? (membrane layers or no, permeable, movement)

have bilayers in membrane, semifluid which makes it semi-permeable and in constant motion but cant flip,

Which lipid has a 4 ring structure, can have different functional groups, and amphipathic?

steroids

Describe the Freeze Fracture technique?

provides views inside the membrane, it splits the lipid bilayer in 2

Define integral membrane proteins

have transmembrane domains (a-helical and contain hydrophobic amino acids) inserted through the membrane

Define peripheral membrane proteins

surface attached

What are cells membranes considered?

mosaic of proteins and others, like steroids embedded in a sea of phospholipids

Can uncharged or charged molecules cross membranes readily and spontaneously?

uncharged

Why does an electrochemical gradient exist across biological membranes? What does it combine to form?

differential movements of ions; combined concentration and electrical gradient

What does creating an electrochemical gradient build up?

potential energy

Does a cells internal and external environments often need to same or different charge and concentration of ions?

different

Define diffusion

spontaneous movement of solutes (small molecules and ions) from a high to low concentration to achieve equilibrium

Define concentration gradient

created by a different in solute concentrations

what is the movement of net movement of solutes?

high to low concentration

What does diffusion along a concentration gradient affect entropy?

increases and spontaneous

Define equilibrium

occurs when molecules or ions are randomly distributed, molecules are still moving randomly but no net movement

Define osmosis

movement of water, a special case of diffusion in presence of a bilayer and concentration gradient of solute

How can water diffuse?

across lipid bilayers in presence of unequal concentrations of solute; Low to high concentration

define tonicity

relative concentrations of solute and movement of solution between inside and outside a cell membrane

what does isotonic mean?

solution outside the cell has about the same solute concentration as the inside

Define hypertonic and hypotonic for the outside solution

hypertonic - higher solute outside than inside hypotonic - higher solute inside than outside

How can ions be transported? What do they cross through?

ion channels down a gradient; through a bridge

Since ion channels form pores, what does that allow?

diffusion of specific ions (high to low)

In an ion channels, where is it hydrophilic and where is it hydrophobic?

hydrophilic - residues inside the pores hydrophobic - residues contacting phospholipids

How do membrane channels open and close in response to a signal?

voltage gated K+ channel and Ligand (signal)-gated channels

What are the 2 transports for molecules and ions

passive and active

Define facilitated diffusion

carrier proteins facilitate diffusion by picking up the solute and transporting it across the membrane to the other end

What do some membrane impermeable solutes use instead of channels?

carrier proteins, they are specific to a solute

How does active transport move substances?

through PM against concentration gradient, proteins called pumps use ATP as energy source and move ions

Why do cells use a sodium-potassium pump?

uses energy in ATP to move Na+ against its electrochemical gradient

With each cycle how is Na+ and K+ pumped

3 Na+ ions are pumped out and 2 K+ ions are brought in

define primary active transport

directly uses ATP to move something against its concentration gradient

How many negatively charges phosphate groups does ATP have?

3

What does facilitied diffusion and active transport require?

a transporter, but diffusion moves solute along a gradient while active transport moves solutes against a gradient

How does energy work for facilitated diffusion and active transport?

energy for diffusion is provided by solute concentration gradient and transport utilizes other sources of energy such as ATP

What does defective CFTR prevent chloride ions to do?

leaving cells that surround airway passage cells, causes mucus to be tick because water doesn't leave

Based on phylogeny, what are the 3 domains organisms are divided into?

bacteria (prokaryotic), archaea (prokaryotic), eukarya (eukaryotic)

based on morphology what are the 2 fundamental cell types?

Prokaryotes and Eukaryotes

how many cells are in the human body?

30-37 trillion

What are the conversions for 1 mm = __ um and 1000 nm = __ um

1000, 1

Describe a light microscope. (type of beam & lens, magnification, resolution)

use light beams and optical lens, magnification 100-1000x, resolves as small as 0.2 um or 200 um

Describe electron microscope. (beam, magnification, resolution)

uses electron beams (shorter wavelengths than light), magnification up to 500,000 x, resolution 2nm

Describe Fluorescence microscope. (how are proteins identified, what kind?)

"tagging" and by green or yellow fluorescent protein

What is a prokaryote cell?

bacteria, lack membrane-bound nucleus, small

What does most bacteria contain?

single chromosome in a nucleoid, ribosomes, plasma membrane, stiff cell wall surrounded by capsid, and few, if any membrane-bounded organelles

What is a eukaryote cell?

"true" nuclei, have membrane-bound organelles in cytoplasm

What does the nucleus do?

processes information

What are the parts in the nucleus and what do they do?

nuclear envelope - separates nucleus from cytoplasm with a double membrane with nuclear pores Chromosomes - DNA and proteins Nucleolus - makes Ribosomal RNA

Where are the ribosomes made, what do they do, and where are they present?

made in the nucleolus, they make proteins & RNA, and present in plant, animal and bacteria

Where are ribosomes attached to?

ER, ( or in cytosol for eukaryotes)

How do molecules get in and out of the nucleus?

nuclear envelope

What is the gateway to the nucleus?

nuclear pores

What is the difference between the rough and smooth ER?

rough - has ribosomes, makes and folds proteins; smooth - no ribosomes, enzymes that make or break down lipids, reservoir for Ca ion

What are a series of stacked, flat, membranous sacs called cisternae?

golgi apparatus

What does a protein have to pass through to leave the rough ER?

golgi apparatus

What does amino acids break down into?

polypeptides (proteins)

What does nucleotides break down into?

nucleic acids (RNA or DNA)

What does monosaccharides break down into?

polysaccharides

What kind of cells are lysosomes found in, and how many different enzymes are contained?

animal cells, 40