bio principles exam 2

mouth

teeth increase surface area available for digestion by enzymes

pharynx

the throat; epiglottis blocks windpipe opening so food is directed to esophagus instead of lungs

esophagus

transports food to stomach by rhythmic waves of muscle contraction (peristalsis)

stomach

where acidic gastric juices break down proteins

small intestine

where most digestions of carbs, proteins, and fats and nucleic acids occur

large intestine

where water is reabsorbed in colon or the undigested produce feces

liver

produces bile which aids absoption of fats

gall bladder

stores bile

pancreas

produces digestive enzymes and produces buffer that neutralizes acidity of the stomach

Robert Hooke

invented the microscope and led to discovery of cells

compound light microscope

magnify x1000
can see human cheek cell

electron microscopy

uses electron beams to see 100,00-2nm

transmission

type of electron microscopy that allows to see inside the cell

scanning

type of elctron microscopy that allows us to see outside the cell ex. projections

prokaryotic cells

- cell that has no nucles
- type of bacteria

coccus
bacillus
spirochete

common shapes of prokaryotes:
- spherical shaped (staphylococcus)
- rod shaped individuals (bacillus cereus)
- s or snake shaped

eukaryotic cells

animal cells
- contain a nucleus
- has organelles

plasma membrane

a fluid phospholipid bilayer that is a selective barrier and allows movement of O2 and H20

nucleus

organelle
- has 2 membranes
- nuclear envelope has pores for rna to travel
- chromatin (uncondensed dna)
- nucleolus actively copies DNA, RNA synthesis

rough ER

organelle has ribosomes; makes proteins

smooth ER

organelle Makes lipids and breaks down toxins; produce plasma membrane

ribosomes

organelle contain RNA and proteiN

golgi complex

organelle process proteins and synthesize polysaccharides
- cisternae appears as flattene folds
- movement of vesicles from cis to trans

lysosome

organelle membrane sac of enzymes that digest macros/enzymes
- pathway: DNA \> RNA \> E.R \> Golgi \> Lysosome

peroxisome

create and destroy hydrogen peroxide H2O2; detoxify alcohols and more

endomembrane system

A network of membranes inside and around a eukaryotic cell that include E.R, golgi, and vesicles

cytoskeleton

composed of a network of microfilaments, intermediates, and microtubules. forms a mesh in cytosol that forms/ disassembles frequently

tubulin

the largest microtubule; central structural support in flagella and cilia.

actin

microfilament. used in muscle movement/ contraction, maintains cell shape, involved in CYTOPLASMIC STREAMING

intermediate filament

type of cytoskeletal filament made of keratin, characterized by an intermediate thickness, and playing a role in resisting cellular tension

motor proteins

reacts with cytoskeleton to promote movement and microtubules act as track guides

lysosomes, centrioles, flagella

organelles not in plant cells

chloroplast

only in photosynthetic organisms
- double membrane
- contain DNA

central vacuole

in plant cells that store, breakdown molecules, and expand cells
(contractive vacuole in animals)

tight junctions

intercellular junction in animal cells; fuses cell membranes to create belts around cells and prevents leaking of fluid

desosomes

intercellular junction in animal cells (anchoring junction) . fasten cells together in strong sheets like rivets

gap junctions

intercellular junction in animal cells (communicating junctions) provide cytoplasmic channels between cells

membrane proteins

oligosaccharides;
- transport, intercellular joining
- enzymatic activity
- cell-cell recognition
- signal transduction
- attachment to cytoskeleton and ECM

passive transport

tranport that requires no energy and follows concentration gradient

simple diffusion

molecules in the liquids and gaseous state are in constant movement

osmosis

the passive transport of water across a semi permeable membrane

hypertonic

(plasmolyzed) Having a higher concentration of solute than another solution. cell shrivels

hypotonic

turgid. have a lower concentration of solutes compared to outside solution. cell becomes lysed and explodes

isotonic

(flaccid) solutions have equal solute concentration (equilibrium)

sodium potassium pump

pumps 3 sodium ions outside the cell, brings 2 potassium ions in

exocytosis

active transport. cell expels cellular waste, vesicle fuses with plasma membrane (ex. neurotransmitters and insulin)

endocytosis

active transport cell eating

pinocytosis

cell drinking. cell creates a vesicle around a droplet of extracellular fluid

phagocytosis

cellular eating where the cell engulfs an organism by packing it in a vacuole and digested when fused with a lysosome

receptor mediated endocytosis

specific process triggered when substances bind to receptors (ligands) on the membrane surface

metabolism

the totality of an organisms chemical reactions

catabolic pathways

metabolic pathway that release energy by breaking down molecules (ex. cellular respiration)

anabolic pathways

metabolic pathway that consumes energy to build molecules (ex. glucose in photosynthesis) energy released by catabolic is used in anabolic

potential energy

energy that matter possess because of location or structure

Kinetic energy

KE \= 1/2mv^2

first law of thermodynamics

law that states energy can be transferre and transformed but it cannot be created or destroyed

second law of thermodynamics

law that states every energy transformation must make the universe more disordered

entropy

is a quantity used as a measure of disorder, or randomness (ex increasing heat)

spontaneous process

processes that occur without outside help; they increase the stability of a system

nonspontaneous processes

processes that can only occur if energy is added to a system ex anabolic reactions such as carbohydrate synthesis; decrease the stability of a system. G is positive

free energy

the portions of a system energy that is able to perform work when temperature is uniform throughout the system

exergonic reaction

proceeds with a net release of free energy and delta G is negative (spontaneous process)

endergonic reaction

reaction that absorbs free energy from surroundings. dela G is positive. store energy. (non spontaneous process)

ATP

(adenosine triphosphate) type of nucleotide with a nitrogenous base adenine, sugar ribose, and a chain of 3 phosphate groups

phosphorylation

the addition of a phosphate group to a molecule to make ATP from ADP. hydrolysis

activation energy

minimum energy required to break chemical bonds. Ea is released back to surroundings. The amt of energy necessary to push reactants over an energy barrier and over the transition state

catalyst

a chemical agent that changes the rate of a reaction without being consumed by the reaction

enzyme

a catalytic protein that speeds up reactions by lowering the activation energy needed. they do not change delta G.

substrate

a reactant which binds to an enzyme. they are held in the active site by hydrogen bonds and ionic bonds

active site

of an enzyme, is a pocket on the surface of a protein into which the substrate fits. the specificity of an enzyme is due to the fit beetween the \__________ \____ and that of the substrate.

induced fit

as the substance binds, the enzyme changes shape leading to a tighter \_______ \___, bringing chemical groups in position to catalyze the reaction

enzymes

- enzymes are substrate specific.
- a single enzyme molecule can catalyze thousands of reactions in a second
- they are unaffected by reaction and reusable
- most metabolic ones can catalyze in forward and reverse

temperature

this factor can speed up rate of reactions as well as denature proteins. each enzyme has an optimal \________

6-8

optimal pH for enzymes

cofactors

many enzymes require nonprotein helpers for catalytic activity

inorganic

this cofactor binds permanently to the enzyme (ex. zinc, iron, copper)

organic

cofactor or coenzyme that includes vitamins (ex. NAD, NADP, FAD)

competitive inhibition

binding by some molecules, inhibitors prevent enzymes from catalyzing reactions

allosteric sitE

A specific receptor on teh enzyme that is not the active site. binding by certain molecules can inhibit or stimulate enzyme activity

noncompetitive inhibition

if the inhibitor binds somewhere other than the active site- the allosteric site- it blocks substrate binding by changing the shape of the active site

feedback inhibition

one of the common methods of metabolic control in which a pathway is turned off by its end product. the end product is an inhibitor of an enzyme in the path.

phosphorylation

the transfer of a phosphate from ATP to another molecule

oxidation

when an atom loses electrons

reduction

gain of electrons

glycolysis

the breakdown of glucose into 2 molecules of pyruvate (3C), 2 ATP and 2NADH. occurs in the cytoplasm and does not require oxygen

krebs cycle and ETC

if O2 is present, after glycolysis pyruvate moves to the \______ and energy stored in NADH is converted to ATP by the \___ and oxidative phosphorylation

substrate-level phosphorylation

ATP is formed by transferring a phosphate group directly to ADP from a phosphate-bearing substrate

acetyl CoA

as a pyruvate enters the mitochondrion, it is modified into \______ \___ which enters the krebs cycle in the matrix

NADH

when you add an electron to NAD+ you get \____

1 ATP
3 NADH
1 FADH2
2 CO2

krebs cycle products per Acetyl CoA

4 NADH
3 CO2
1 FADH
1 ATP

total energy yield from krebs cycle per molecule of pyruvate

8 NADH
6 CO2
2 FADH2
2 ATP

total energy yield of krebs cycle per molecule of glucose

KREBS CYCLE

occurs in the mitochondrial matrix in the presence of oxygen. oxidizes pyruvate into CO2

oxidative phosphorylation

produces ATP within the mitochondrial membrane as electrons are passed along the ETC. it produces 90% of ATP generated by respiration

chemiosmosis

the coupling of redox reactions of the ETC to ATP synthesis by oxidative phosphorylation

glucose \> NADH \> ETC \> H+ \> concentration gradient \> ATP

during respiration, energy flows from ....

fermentation

process that occurs without oxygen to produce ATP from glucose by substrate level phosphorylation

alcohol fermentation

pyruvate is converted into ethanol

lactic acid fermentation

pyruvate is reduced directly by NADH to form lactate (used to make cheese and yogurt)

thylakoid

a flattened membrane sac inside chloroplast where light dependent reactions occur