Biology Exam 2

prokaryotic cell

simple cell w/ no membrane-bound organelles. They are unicellular, no nucleus

Eukaryotic cells

membrane-bound organelles which each carry out specific functions. These organelles allow cells of a multi-cellular organism to take o a specific task as a part of a greater whole. has a nucleus

What structures do prokaryotes and eukaryotes have in common?

cell membrane, cytoplasm, DNA, ribosomes

plasma membrane

an outer covering that separates the cell's interior from its surrounding environment; selectively permeable (in both cells)

fluid mosaic model

model that describes the arrangement and movement of the molecules that make up a cell membrane; components of plasma membrane as mosaic- phospholipids, cholesterol, proteins, carbohydrates

Cytoplasm

the entire region between the nucleus and the plasma membrane

Ribosome

Makes proteins in both cells

Which is bigger prokaryotes or eukaryotes?

eukaryotes are bigger

pili

short, hairlike protein structures on the surface of some bacteria

Flagella

whiplike tails found in one-celled organisms to aid in movement

capsule

A sticky layer that surrounds the cell walls of some bacteria, protecting the cell surface and sometimes helping to glue the cell to surfaces.

cell membrane

A cell structure that controls which substances can enter or leave the cell.

nucleoid

A dense region of DNA in a prokaryotic cell.

cytosol

The soluble portion of the cytoplasm, which includes molecules and small particles, such as ribosomes, but not the organelles covered with membranes.

Cytoskeleton

A network of fibers that holds the cell together, helps the cell to keep its shape, and aids in movement

organelles don't just float in cells

3 fibers of cytoskeleton

microtubules, microfilaments, intermediate filaments

Mircotubules

made of tubulin proteins; arranged into thin, hollow tubes;

Job is to maintain cell shape, cell motility, chromosome movement in cell division, organelle movement

microfilaments

Made of the protein actin; arranged into thin, solid rods;

Job is to maintain cell shape, change cell shape, muscle contraction, cytoplasmic streaming in plant cells, cell motility, division of animal cells

intermdiate filaments

made of different proteins;

Job is to maintain cell shape, anchorage of nuclues and certain organelles, formation of nuclear lamina

what does the nucleus protect

DNA

Chromitin

the DNA and protein components of chromosomes, visible as clumps or threads in nuclei

What are ribosomes made of?

rRNA and proteins (2 subunits: large and small)

why are blood cells red

hemoglobin

Hemoglobin

An iron-containing protein in red blood cells that reversibly binds oxygen.

What are membranes made of?

phospholipids, cholesterol, carbohydrates, proteins

Lysosome

digestive vesicles (recycle) very acidic so it will only work at a low pH so it can't eat a whole cell

Phagocytosis

A type of endocytosis in which a cell engulfs large particles or whole cells

theory of endosymbiosis

This theory states that cell organelles, like mitochondria, were once tiny, free-living prokaryotic organisms that took up permanent residence inside larger prokaryotic organisms.

Autophagy

A process in which lysosomes decompose damaged organelles to reuse their organic monomers

Peroxisomes

metabolizes vesicles

vesicle

A membrane bound sac that contains materials involved in transport of the cell.

Vacuole

A sac inside a cell that acts as a storage area

Mitochondria

where cellular respiration occurs. In plants and animals

Chloroplast

Contains chlorophyll for photosynthesis

Centrosome

to organize the cytoskeleton

endomembrane system

starts with nuclear membrane and continues physically with the ER (that is folded on itself). It also has a Golgi apparatus and plasma membrane. Vesicles will move inbetween them

Golgi apparatus

serves as a kind ofpackaging center: Transport vesicles deliver materialsto the cis face.

Plasmodesmata

channels through cell walls (through their pours) that connect the cytoplasms of adjacent cells.

tight junctions

-Watertight seal between cells

-Plasma membranes fused with a strip of proteins

(animal cell)

desmosome

act like spot welds between adjacent epithelial cells, the cadherins protein connect to intermediate filaments

(animal cell)

gap junction

A type of intercellular junction in animals that allows the passage of materials between cells.

intergal proteins

integrated into membrane structure and hydrophobic membrane-spanning regions interact w/ hydrophobic region of phospholipid bilayer; has hydrophilic region(s) and 1 or + mildly hydrophobic regions

Carbohydrates correlation with Plasma membranes

found exterior surface of cell and bind to glycoproteins or glycolipids, collectively called glycocalyx

What affects membrane fluidity?

Temperatures (increase temps= increase futility)

Saturation of fatty acid tails (cis double bonds in fatty acid tails make membrane more fluid unsaturated also makes more fluid)

Cholesterol (at high temp cholesterol can lower fluidity, at low temp cholesterol can increase fluidity)

passive transport

the movement of substances across a cell membrane without the use of energy by the cell; substances move from higher concentration to lower concentration

simple diffusion

Movement of molecules from an area of higher concentration to an area of lower concentration. uses no energy. small, nonpolar molecules can diffuse across plasma membrane

facilitated transport (diffusion)

diffusion with the help of transport proteins. Can be channels for material or carriers. does not require extra energy

channel proteins

have a hydrophilic channel that certain molecules or ions can use as a tunnel

carrier proteins

bind to molecules and change shape to shuttle them across the membrane

osmosis

Diffusion of water through a selectively permeable membrane

hypertonic solution

a solution that causes a cell to shrink because of osmosis (water leaves)

isotonic solution

A solution in which the concentration of solutes is essentially equal to that of the cell which resides in the solution

hypotonic solution

A solution in which the concentration of solutes is less than that of the cell that resides in the solution (water goes in)

how is hypertonic and hypotonic different between animal and plant cells

in hypertonic the cell and plasma membrane shrink away from cell wall. In hypotonic solution it does not burst, instead it would just be pushed against cell wall.

active transport

Energy-requiring process that moves material across a cell membrane against a concentration difference

primary active transport

3 Na attach along with an ATP that causes the Na to go to other side and one P to stay attached then 2 K attach and go to other side with the P flying off

secondary active transport

Form of active transport which does not use ATP as an energy source; rather, transport is coupled to ion diffusion down a concentration gradient established by primary active transport.

electronchemical gradient

on outside Low [K] but high [Na]. inside plasma membrane high [K] but low [Na]

proton pump

An active transport protein in a cell membrane that uses ATP to transport hydrogen ions out of a cell against their concentration gradient, generating a membrane potential in the process.

Exocytosis

Process by which a cell releases large amounts of material

Pinocytosis

A type of endocytosis in which the cell ingests extracellular fluid and its dissolved solutes.

receptor-mediated endocytosis

The movement of specific molecules into a cell by the inward budding of membranous vesicles containing proteins with receptor sites specific to the molecules being taken in; enables a cell to acquire bulk quantities of specific substances.

Gibbs free energy

change in free energy, energy available to do work. measure of stability (the less of gibbs free energy the more stable it is)

spontaneous reaction

has a negative change in free energy. a reaction that will happen on its own

exergonic reaction

spontaneous. energy released

endergonic reaction

non-spontaneous. energy required

endergonic reaction graph

exergonic reaction graph

Hydrolysis of ATP

Releases 7.3 kcal/mole energy to do work. Reaction favors formation of products. Energy liberated is used to drive a variety of cellular processes.

What is the purpose of energy coupling? in hydrolysis of ATP

it makes the overall reaction exergonic.

enzymes

Catalysts for chemical reactions in living things. Is used to lower activation energy. not a product not a reactant and cant change the free energy.

How are enzymes regulated by the cell?

by noncompetitive and competitive inhibition, allosteric change, feedback inhibition, gene expression, cellular localization and activators

redox reaction

A chemical reaction involving the transfer of one or more electrons from one reactant to another; also called oxidation-reduction reaction.

oxidized

loss hydrogens

reduction

gain hydrogen

Compare substrate-level phosphorylation and oxidative phosphorylation

both their ultimate production is ATP

substrate-level phosphorylation

The enzyme-catalyzed formation of ATP by direct transfer of a phosphate group to ADP from an intermediate substrate in catabolism.

oxidative phosphorylation

The production of ATP using energy derived from the redox reactions of an electron transport chain; the third major stage of cellular respiration.

What is the role of NAD+ and FAD in cellular respiration?

function as electron shuttles. keep going

What is the reduced and oxidized form of both of these coenzymes? for NAD+ and FAD

NAD+ is reduced when it goes to NADH. NADH is oxidized when it goes to NAD+.

FAD is reduced when it goes to FADH2. FADH2 is oxidized when it goes to FAD.

Glycolysis

-takes place in the cytosol.

-the inputs are glucose.

-Outputs are 2 molecules of pyruvate, ATP, NADH

-The glucose oxidizes.

-NAD+ reduces

Transcription of gene in nucleus → translation of mRNA in cytosol(cytoplasm) on free ribosomes → release of protein

Pyruvate oxidation

-takes place in the mitochondrial matrix.

-the inputs are pyruvate.

-the output is 1carbon dioxide, 1 NADH, and acetyl CoA

-NAD+ reduces.

-pyruvate oxidizes

Citric Acid Cycle

-takes place in the mitochondrial matrix.

- input: Acetyl-CoA

-output: 2carbon dioxide, 3NADH, 1FADH2, and 1ATP

-isocitrate is oxidized

-NADH and FADH2 are reduced

Electron Transport chain

-takes place in inner mitochondrial membrane

-input: NADH, H+, ADP, FADH2, O2

-output: NAD+, 26 ATP, FAD, H2O

-NADH and FADH2 are oxidized

-hydrogen is reduced

ETC within the thylakoid membrane

moves protons across the thylakoid membrane into the lumen. the energy is used from the electrons

ATP synthase

a channel protein that makes ATP from protons moving down their concentration gradient. The hydrogen ions will flow down (from high to low) and use the energy it makes to make ATP

two types of fermentation

alcoholic and lactic acid

What is the purpose of fermentation

to recycle back NADH to NAD+ (back to glycolysis)

lactic acid fermentation

When pyruvate has no where to go so the 2 NADH get there oxygens taken off and go with NAD+

alcohol fermentation equation

pyruvic acid→ acetaldehyde + NADH → ethanol NAD⁺

When in cellular respiration is the presence or absence of oxygen a deciding factor in which path to take?

glycolysis

where in the mitochondria the citric acid cycle and ETC take place

high H+ is the top and low H+ is at bottom

What are in the inputs and outputs for the light reactions of photosynthesis?

inputs: H2O, light, NADP+, ADP and Pi

outputs: O2, ATP, NADPH

general photosystem

composed of a reaction center surrounded by numerous light harvesting complexes

What is the difference between Photosystem I and Photosytem II?

the reactions of photosystem II occur in the Calvin cycle, whereas the reactions of photosystem I occur outside of the Calvin cycle

pigments

absorb specific wavelengths of visible light. It is there to absorb light energy

thylakoid membrane

the path of electron through the light reactions

What are the inputs and outputs for the Calvin cycle of photosynthesis?

inputs: CO2, ATP, NADPH

output: ADP, NADP+

What are the three steps of the Calvin cycle

carbon fixation (takes 6 ATP), reduction (reduce 6 NADPH), regeneration (take 3 ATP)