BIO chapters 3, 4, 5

Scott Matthews

what are the 3 components of the cell theory?

1 - cells are the basic unit of life

2 - organisms are made up of 1 or more cells

3 - all cells arise from pre-existing cells

what is the difference between magnification and resolution?

magnification - enlarging the size of an object

resolution - the ability to distinguish between 2 close objects

what total magnification can be obtained using a light microscope and an electron microscope?

light microscope - 1000

electron microscope - 100,000

what are the smallest objects observable using both types of microscopes?

light microscope - cells

electron microscope - molecules

what are 4 features shared by all cells?

DNA, ribosomes, cytosol, plasma membrane

why are most cells small?

to maximize their surface area to volume ratio

why is the surface area to volume ratio so important?

it improves the efficiency of getting things in and out of the cell, and improves communication

how many cell types are there?

2 main groups - prokaryotic, eukaryotic

what are 4 primary differences between prokaryotes and eukaryotes?

prokaryotes - no nucleus, no organelles, relatively small, less complex

eukaryotes - has nucleus, has organelles, relatively large, more complex

how many domains are there?

3

what are 2 characteristics of Bacteria, Archaea, and Eukarya?

bacteria - prokaryotic, no organelles

archaea - prokaryotic, no organelles

eukarya - eukaryotic, have organelles

what’s the anatomy of a generalized prokaryote?

plasma membrane, cell wall, capsule, cytosol, DNA within nucleoid, ribosomes

what are the chemical properties of the head and tail of phospholipids?

head - hydrophilic

tail - hydrophobic

what is the flluid mosaic model?

it describes the nature or chemistry of the phospholipid bilayer

what are 3 types of membrane proteins?

TEA - transport proteins, enzymes, adhesion proteins

what is the endomembrane system?

a system of internal membranes in a eukaryotic cell

what organelles are part of the endomembrane system?

nuclear envelope, endoplasmic reticulum, Golgi apparatus, lysosomes, peroxisomes, vacuoles, cell membrane

what is the function of the nucleus?

it stores and protects DNA

how many membranes make up the nuclear envelope?

2

what are nuclear pores, nucleoplasm, and nucleolus?

nuclear pores - let things in and out of the nucleus

nucleoplasm - the fluid of the nucleus

nucleolus - the storage site for ribosomes

what is the difference between chromatin and choloplasts?

chromatin - general contents of the nucleus (DNA, RNA, proteins)

chromosomes - piece of DNA that you find in a cell

what is the endoplasmic reticulum?

it has the smooth ER (no ribosomes) and a rough ER (ribosomes)

what are ribosomes?

the site of protein synthesis

what are free and bound ribosomes, and where are they found within cells?

bound ribosomes are found on the rough ER

free ribosomes are found in the cytosol

what are 2 functions of the smooth and rough ER?

rough ER - proteins synthesis, store/modify/ship out proteins

smooth ER - does not make proteins, detoxify things

what are 3 functions of the golgi apparatus?

modifies, stores, and receives/ships

what are the functions of lysosomes, vacuoles, and peroxisomes?

lysosomes - hold digestive/hydrolytic enzymes

vacuoles - storage organelle

peroxisomes - break down hydrogen peroxide (H2O2)

what reaction occurs in mitochondria, and what energy carrier is synthesized as a result?

cellular respiration (C6H12O6 + 6O2 → 6H2O + ATP), energy carrier is ATP

how many internal compartments do mitochondria have?

2 compartments

what is the mitochondrial matrix?

the inner chamber of the mitochondria

what are cristae?

finger like folds within the mitochondria

what reaction occurs in chloroplasts, and what energy carrier is synthesized as a result?

photosynthesis (6CO2 + 6H2O → C6H12O6 + 6O2), energy carrier is glucose

how many membrane layers do chloroplasts contain?

3 layers (2 inner + 1 interconnected)

what are stroma, granum, and thylakoid membranes?

stroma - fluid filled compartment of the chloroplast

granum - stack of thylakoids

thylakoid - single membrane (pancake)

what is the cytoskeleton?

the internal skeleton of cells (made of microtubules, intermediate filaments, and microfilaments)

what is 1 function of microtubules, intermediate filaments, and microfilaments?

microtubules - cell movements

intermediate filaments - anchorage of organelles

microfilaments - maintenance of cell shape

what are actin and tubulin?

actin - building blocks of microfilaments

tubulin - building blocks of microtubules

what are motor proteins?

they move things up and down microtubules

what are cilia and flagella?

they are projections of the plasma membrane

flagella - tail located on sperm

cilia- shorter, more abundant

what is the 9 + 2 pattern?

the internal structure of microtubules inside cilia and flagella (9 pairs outside, and 2 microtubules inside)

what is the primary function of tight, anchoring, and gap junctions?

tight junction - prevent leaking

anchoring junction - hold animal cells together

gap junction - allow the exchange of substances between cells

what is the primary function of plasmodesmata?

allow substances to move between plant cells

what is the endosymbiont theory?

the origin of eukaryotes

what are 4 pieces of evidence that support the endosymbiont theory?

1 - mitochondria and chloroplasts have prokaryotic DNA

2 - similar size/shape between the mitochondria/chloroplasts and prokaryotes

3 - organelles have prokaryotic ribosomes

4 - mitochondria/chloroplasts divide by binary fissions, like bacteria

what is energy?

the ability to do work or make change

what are potential and kinetic energy?

potential - stored energy

kinetic - energy in motion

what are the 3 types of work required by all cells?

chemical, transport, and mechanical

what are the first and second laws of thermodynamics?

1 - energy can’t be created or destroyed

2 - energy transformations are inefficient

what is metabolism?

the collection of all the chemical reactions in the body

what are exergonic and endergonic reactions?

endergonic - reactions that require energy (low to high)

exergonic - reactions that release energy (high to low)

what are oxidation-reduction (redox) reactions?

some things are gaining or losing electrons

what is an electron transport chain?

allow electrons to move through them to do work

what is the cellular currency?

ATP

what are the 3 components of ATP?

RAT - ribose, adenine, triphosphate

what is the ATP/ADP cycle?

ATP spends energy and loses a phosphate, turning it into ADP, in which energy comes back in to become ATP

what are enzymes?

catalysts (make reactions occur faster)

what is activation energy?

Ea, the energy that’s required to make a reaction occur

what is negative feedback?

a way to control or regulate enzymes

what are competitive and noncompetitive inhibition?

noncompetitive - when a substrate sticks to the allosteric site to stop the enzyme

competitive - when a substrate sticks to the active site

what’s diffusion?

movement of substances from an area of high concentration to low concentration until equilibrium is met

what are simple and facilitated diffusion?

simple - substance move across the membrane without help from transport proteins

facilitated - substances move across the membrane with help from transport proteins

what is passive transport?

does not require energy to move substances from high to low concentration

what is osmosis?

movement of water from high concentration towards low concentration across a semi permeable membrane until equilibrium is met

what are the terms of tonicity?

1 - hypertonic

2 - hypotonic

3 - isotonic

what’s the meaning of the tonicity terms and their impact on osmosis in red blood cells?

Isotonic - same solute concentration, RBC remains the same

hypertonic - water has more solutes, RBC has less solutes, then crenation occurs (less water in RBC, then shrinks)

hypotonic - water has less solutes, RBC has more solutes, then lysis occurs (RBC gains water, then bursts)

what is active transport?

requires energy to move substances from low concentration to high concentration

what are endocytosis and exocytosis?

endocytosis - process of moving things inside the cell

exocytosis - process of moving things outside the cell

what is phagocytosis?

cells eating large things

what are autotrophs and heterotrophs?

autotrophs - self feeding organisms that create their own biomolecules

heterotrophs - have to ingest food

what is the balanced equation for photosynthesis?

6CO2 + 6H2O → C6H12O6 + 6O2

what are 2 ways that plants sue carbohydrates made during photosynthesis?

1 - use to make ATP

2 - they store glucose as starch

what is the electromagnetic spectrum?

a collection of all the different forms of light

what are photons?

a particle of light

how does the wavelength of various forms of radiation relate to their energy?

short wavelength - high energy

long wavelength - low energy

what is the range in wavelength (nm) of visible light?

380 to 760

what are photosynthetic pigments?

light sensitive pigments/proteins that respond to light energy

what colors do chlorophyll a, chlorophyll b, and carotenoids reflect?

chlorophyll a - dark green

chlorophyll b - light green

carotenoids - orange

what occurs in the mesophyll?

photosynthesis

what are the 2 stages of photosynthesis?

1 - light reactions (in thylakoids)

2 - carbon reactions/calvin cycle (in stroma)

what are the reactants and products of the light and carbon reactions?

light - reactant is H2O, product is O2

carbon - reactant is COs, product is C6H12O6

what is a photosystem, and where are they found?

a collection of protein systems designed to absorb sunlight energy, are found in thylakoids

what happens when light strikes an antenna molecule?

it gets redirected to the reaction center

what is the function of a reaction center?

to give up electrons

why is water required in the light reactions?

for its electrons

in a non-cyclic pathway, where are excited electrons shuttled?

NADPH

what work is accomplished as electrons are moved through the electron transport chain?

active transport

at the 2nd photosystem (photosystem I), what’s required to reenergize the electron to produce NADPH

more light energy

how is ATP synthase involved in the production of ATP?

the more hydrogen there is, the more it wants to escape, which happens by moving through ATP synthase

what are 4 structures/organelles unique to plants?

cell wall (cellulose), chloroplast, large central vacuole, plasmodesmata (pores)

what are the 3 steps of the calvin cycle?

carbon fixation, PGAL synthesis, regeneration of RuBP

what generally occurs at each step of the calvin cycle?

carbon fixation - adding carbons together

PGAL synthesis - converting PGA into PGAL

regeneration of RuBP - generation of RuBP

how many carbon atoms are found in 1 molecule of of RuBP, CO2, PGA, PGAL, and glucose?

RuBP - 5 carbons

CO2 - 1 carbon

PGA - 3 carbons

PGAL 3 carbons

glucose - 6 carbons

what is the enzyme responsible for combining RuBP with CO2?

RUBISCO

what is required to convert PGA into PGAL?

ATP + NADPH (energy from last reactions)

what is required to convert PGAL to RuBP?

ATP

what occurs if RuBP is not available?

photosynthesis can’t happen

what is photorespiration?

when oxygen enters the calvin cycle instead of carbon

how are C3 plants similar to C4 and CAM plants?

they all do photosynthesis