Exam 2 study guide

3 basic parts of the cell

cell membrane, nucleus, cytoplasm

principles of cell theory

all living things are made of cells, cells are the basic unit of life, cells arise from pre-existing cells, hereditary info is passed from cell, all cells have basic chemical composition, energy flow occurs within cells

cell membrane

Separates insides of cell from the outside environment. Dictates what passes through the cell

defining characteristic for difference between prokaryotic and eukaryotic cells

Prokaryotes don’t have a nucleus, eukaryotes do have a nucleus

this type of cell HAS a nucleus

eukaryotic

this type of cell does NOT have a nucleus

prokaryotic

ribosome function

synthesize proteins

structure used during bacterial conjugation

pili

know these structures:

cell membrane, nucleoid, flagella

Antoni van Leeuwenhoek

Father of Microbiology. discovered cells with microscope

function of the endomembrane system

modifies, transports, and packages proteins and lipids in the cell

cell junctions found in animal cells

tight junctions, adhering junctions, gap junctions

cell junctions found in plant cells

plasmodesmata

tight junctions

fasten cell membranes of adjacent cells together, keep bodily fluid contained

adhering junctions

make up cardiac muscles and skin

gap junctions

closable channels between cells; let substances flow quickly between cells

plasmodesmata

open channels between cytoplasm of two cells, similar to gap junction in animal cells.

what are the different structures cells use to move

motor proteins, cilia, pseudopods

exocytosis

moving something inside the cell to the outside. movement of vesicles and their content outside of the cell

ATP

cell currency, produces energy

chemical energy

energy stored in chemical bonds

kinetic energy

the energy of motion; type of energy associated with movement

potential energy

stored energy related to something's position

autotrophs

make own food using the sun's energy; producers

heterotrophs

doesn't make own food, eats others for energy; consumers

first 2 laws of thermodynamics

1: energy can't be created or destroyed
2: energy tends to disperse

exergonic reactions

energy releasing, spontaneous

endergonic reactions

energy consuming; need energy

catabolism

destroys; uses and produces energy

anabolism

builds; uses energy

metabolism

chemical reaction in body's cells that change food into energy

energy

ability to do work; ability to cause some kind of change

activation energy

minimum amount of energy needed to start a chemical reaction

enzymes are..

reusable

coenzymes are..

not reusable

where does catalysis occur on enzymes

the active site

difference between linear and cyclic pathways

linear reactions happen in order and stop. cyclic reactions happen in order and the last one restarts the reaction chain

receptor proteins

Trigger change in cellular activity in response to stimuli

adhesion proteins

Fasten cell’s membranes together

transport proteins

Transports substances across lipid bilayer

enzymes

Catalyzes reactions at membrane

active use of transport proteins

requires energy to move across cell membrane, goes against gradient differences

passive use of transport proteins

doesn't require input to happen

phosphorylation

donates phosphate group to enzyme which donates to reaction

diffusion

spontaneous spreading of molecules or atoms through a fluid or gas

catalysis

speeds up reactions

osmosis

the movement of fluid across membranes

where does photosynthesis occur in eukaryotic cells?

chloroplasts, thylakoid, stroma

visible light

light with a wavelength of 380-750nm

different colors come from..

different wavelengths of light

photon energy is () to wavelength

inverse

what pigment gives plants their green color

chlorophyll a

photon

a particle of light

Theodor Engelmann

Discovered sunlight is driver for photosynthesis, hypothesized color of light affects photosynthesis; blue and red are best for driving photosynthesis

where do light dependent reactions take place?

the thylakoid membrane

cyclic light dependent reactions use..

PSI

noncyclic light dependent reactions use..

PSI and PSII

what flows through the ATP synthase to trigger phosphorylation

H+ ; hydrogen ions

products of cyclic light dependent reactions

ATP

products of noncyclic light dependent reactions

ATP, NADPH, Oxygen

carbon fixation

taking carbon atoms from inorganic molecules (CO₂) to attach them to organic molecules (sugar)

products of light independent reactions

sugars (glucose)

where do light independent reactions occur

stroma

this enzyme starts the Calvin Cycle (light independent reactions)

rubisco

most molecules of PGAL are () back into the Calvin Cycle

recycled

C3 Plants

fix carbon by the calvin cycle. 85% of modern plants. produces CO2 and ammonia during photorespiration

C4 Plants

fix carbon twice. 3% of modern plants. minimizes photorespiration

CAM Plants

fix carbon twice. stomata open at night, conserve water, desert plants. 12% of modern plants

carbon dioxide is a ( ) of photosynthesis [product or reactant]

reactant

DNA is stored here in eukaryotic cells

nucleus

what structure do photosynthetic eukaryotes NOT use during photosynthesis

cytoplasm

T/F photons with high energy will have longer wavelengths

False

the transport protein ATP synthase using what to activate and attach a phosphate group to make ATP?

hydrogen ions

this type of plant only uses the basic steps of the calvin cycle (only fixes carbon once)

C3 Plants

how did oxygen negatively affect the Earth

it was toxic, it polluted the air

Great Oxidation Event

killed off most anaerobic life, triggered an ice age, gave rise to multicellularity.

oxidative stress

Free radicals accumulating and stopping the mitochondria from functioning, damages tissues.

aerobic

can live in the presence of oxygen

anaerobic

without oxygen

antioxidants

minimizes damages caused by oxygen

glycolysis

this process happens in the cytoplasm

glycolysis produces..

ATP by converting glucose to pyruvate

what does oxygen do during electron transfer phosphorylation?

O₂ accepts electrons from transfer chain and other H+. creates H₂O

why is fermentation less efficient than aerobic respiration

It doesn’t fully break down glucose and only produces 2 molecules of ATP vs aerobic respiration producing 36 molecules of ATP