Cell Bio Exam 1 Flashcards Ch. 1, 2, 3, 13, 14,

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cell theory

“cells are building blocks of living tissues”, generated only from pre-existing cells and inherit their characteristics

central dogma

DNA → RNA → protein
replication, transcription, translation,

viruses

exception to central dogma, aren’t alive bc of this, multiply using our DNA (host cell), cannot replicate any other way, some single/double stranded, some DNA/RNA

light microscope

living cells glow, entire cell is visible but you can’t see details, most basic everyday use microscope

electron microscope

use electrons to view very small things like organelles,

confocal microscope

doesn’t use whole light, but a laser, 1 direct beam of light, can view more details

differences between prokaryotes + eukaryotes

eukaryotes have a nucleus + mitochondria, larger + complex, multicellular, always have compartmentalized organelles
prokaryotes are smaller w/ no organelles, can adapt to extreme environments + are most diverse, small unicellular organisms

ribosomes

make proteins, catalyze translation,

mitochondria

oxidate food molecules (carbs, fats, proteins) to generate ATP, contain their own DNA + reproduce themselves (like bacteria)

chloroplasts

mitochondria for plants, help with photosynthesis,

endoplasmic reticulum

highway of the cell, make proteins + ship them out based on form and function,

golgi body

sorts proteins out to different locations, receives proteins from ER

lysosomes

waste disposal system
membrane bound
use enzymes
house intracellular degradation
-break down food to release back to cell as energy
break down waste for recycling + excretion

perixosomes

chemical plant, small membrane enclosed vesicles
contained environment for H₂O₂ rxn, bc it’s dangerous to rest of cell
H₂O₂ generated + degraded, used for specific rxns,

cytoskeleton

allows directed movement, support weight of cell similar to skeleton
helps with changing internal environment of cell (endocytosis - in + exocytosis - out)

Model organisms

simple organisms that can be researched, helps us learn about our own genome

Escherichia Coli

E. Coli, model prokaryote, divides fast, single circular double-stranded DNA, produces many proteins

saccharomyces cerevisiae

yeast, model eukaryote, single-celled, rapidly divides,

arabidopsis thaliana

wall cress, complete DNA sequence is known, produces thousands of offspring very quickly, useful for genetic + hereditary studies

drosophila melanogaster

fruit fly, easiest organism to use for genetics, has provided the most information about cause and effect from DNA instruction to structure than any other organism

caenorhabditis elegans

weird worm thingy, brain’s neurons are completely known, helped us understand programmed cell death, helped us understand fetal alcohol syndrome through behavioral change + brain development changes

danio rerio

zebra fish, transparent when first born, easy to observe organs + how they grow/change, more efficient to study as one can be studied constantly,

homo sapiens

humans, most important model organism, 100% of prescribed drugs are tested on humans thru clinical trials

mus musculus

mouse, can observe social skills + brains b/c of similarity to humans, can have same diseases as humans = important for research

primary cell culture

isolated directly from live organism, behave like normal cells, mortal, downside is needing constant supply,

immortalized cell line

‘transformed’ cells grow infinitely = cancer, unlimited uses, can be used to study cell behavior, response to drugs + environment, don’t behave normally or do anything other than just grow

covalent bonds

2 atoms share electron pair, molecular marriage = strong bond

ionic bonds

electrons donated by one atom to another, taking instead of sharing, after donating both atoms become charged ions, weak bond,

electrostatic attraction

attractive force occurring btwn oppositely charged atoms
cations = +
anions = -

hydrogen bonds

holds together water, charges are exposed due to bent structure, weaker than covalent bonds, last for short time,

hydrophilic vs. hydrophobic

water lovers, charged atoms + polar groups, can dissolve
water haters, insoluble, uncharged + nonpolar

polymerization

monomers forming into polymers by joining through covalent bonds

sugars

make polysaccharides, consist of 100s-1000s of monomers

glycosidic bond

condensation rxn: creates bond, water is expelled as bond forms
hydrolysis: breaks water bond, water is consumed
both rxns are reversible

fatty acids

make lipids, long hydrocarbon chain (hydrophobic)
carboxyl group: has a charge (hydrophilic) chemically reactive,
insoluble in water + soluble in fat

fatty acids are amphipathic

both hydrophobic + hydrophilic regions

saturated vs. unsaturated fat

saturated: no double bonds, solid at room temp, can clog arteries = unhealthy, meat + dairy
unsaturated: have at least 1 double bond, bonds produce kinks, more rigid + can’t move, liquids @ room temp (olive/corn oil), healthier

amino acids

make proteins, consist of: carboxyl group (C), amino group (N), both linked to carbon atom,
side chain (R group) = only variable

type of bond in amino acids

peptide bond = covalent bond between adjacent amino acids
structural polarity = N —> C

nucleotides

monomer for nucleic acids: long polymer of covalently bound nucleotide subunits,
direction: 5’ → 3’
phosphodiester bond: covalent bond that holds backbone together

DNA vs. RNA

DNA bases: A, G, C, T, double stranded
RNA bases: A, G, C, U, usually single stranded, but not always

surface molecules allow macromolecules to bind to other molecules ___

"transiently”, temporary, short-lived attachment between molecules that breaks easily

metabolism

cells extract energy from environment + convert energy stored in chemical bonds

catabolic vs. anabolic

catabolic: breaks down food into smaller molecules, useful form of energy,
anabolic: makes larger molecules, uses energy released from catabolic rxns to create molecules

metabolic pathways

connected in series, product made from one step is the starting material for the next rxnen

enzymes

accelerate, or catalyze specific rxns by lowering the activation energy
highly selective,
unique shape with an active site for very specific substrate = lock + key model
degrades if temperature or pH is too high

rate of enzyme reactions depend on:

how strong the bonds are
how tightly the molecules fit
how often they collide
how much substrate exists in the cell
activity + quantity of enzyme in cell
ALL HIGHLY REGULATED

entropy

how disorder is measured, heat is energy in its most disordered form

photosynthesis vs. cellular respiration

photosynthesis: converts electromagnetic energy from sunlight into chemical energy for plants
respiration: used by most living organisms, break down sugars and oxygen to make water and carbon dioxide, regular breathing

free energy + biological rxns

reactions can be coupled together if they share intermediates
energy released as a product from one rxn can be used as a reactant in another rxn

ATP

most abundant energy source in cells, only usable form of energy by body

energy carrier + importance

takes free energy from favorable rxn to drive unfavorable rxn, helps control what cell does to make sure everything is regulated
-ATP, NAD, NADH⁺

glycolysis

starts with glucose, doesn’t need oxygen (anaerobic), occurs in cytoplasm
produces 2 pyruvate, 2 ATP, 2 NADH,

transition step to krebs cycle

pyruvate oxidized to acetyl-CoA, happens in mitochondria, lipids can also be converted to acetyl-CoA, pyruvate dehydrogenase = main enzyme

krebs cycle

occurs in mitochondrial matrix, starts with acetyl-CoA + ends with 3 NADH, GTP, FADH2, doesn’t need oxygen

oxidative phosphorylation

last step, only step that needs oxygen, produces the most ATP (30-32), oxidation of food molecules reduces O2 to H2O, energy released as byproduct

Gluconeogenesis

glycolysis in reverse, skips some steps, takes a LOT of energy, performed when body is low on glucose, very tightly controlled + not safe → “fight or flight”
starts with lactate

electron transport chain

energy from electrons traveling turns proton pump on + moves protons across membrane, creates gradient which spins ATP synthase + generates lots of ATP

pyruvate oxidation

links stage 1 + stage 2 (glycolysis + krebs cycle) of cellular respiration, is step 1.5,
occurs in mitochondria

lipids energy production compared to sugars

lipids produce 6 times as much

glycogen

multi-branched polysaccharide of glucose
glycogen synthase: makes glycogen
glycogen phosphorylase: breaks glycogen

starch

plant version of glucose for animals,

what type of fat do plants have

unsaturated

all parts of mitochondria

matrix: space with lots of enzymes needed for oxidation of pyruvate + fatty acids and for krebs cycle
inner membrane: contain proteins that conduct oxidation rxns of ETC + ATP synthase which makes ATP
intermembrane space: several enzymes use ATP passing out of matrix to phosphorylate other nucleotides
outer membrane: semipermeable to certain molecules, has channel proteins within phospholipid bilayer

How do mitochondria divide?

reproduce by fission like bacteria, self-divides

where in the body are mitochondria most frequent and most needed?

heart and brain b/c of high-energy functions

similarities btwn chloroplasts + mitochondria

both have their own ribosomes to make their own proteins w/ own special DNA
both look similar to bacteria
both have inner/outer membranes, intermembrane space, + DNA

differences btwn chloroplast + mitochondria

mitochondria has matrix
chloroplast has stroma (matrix equivalent), thylakoid membrane + thylakoid space

why is mitochondria useful to plants

plants use chloroplasts for photosynthesis + give the product (sugar) to mitochondria for krebs cycle so ATP can be made