cellular energetics vocab

anaerobic

no O₂ is required

alcohol fermentation

it turns NADH into NAD+ by taking a pyruvate and turning it into ethanol and CO₂

substrate level phosphorylation

the maker of ATP, when a sugar molecule with phosphate is put into a kinase enzyme with ADP, you create ATP, but it makes a very small amount of ATP

lactic acid fermentation

it turns NAHD into NAD+ by taking a pyruvate and turning it into lactic acid

glycosis

the breaking down of glucose (splitting sugars), no organelles are required (all cells can do this), no O₂ is required, but it only producers a little energy

NAD+

an electron carrier (piggy bank) that has lost an electron

NADH

an electron carrier (piggy bank) that has gained an electron

krebs cycle

it oxidizes the pyruvate, the pyruvate loses an electron, the electron goes to NAD+ which then turns into NADH

oxidative phosphorylation

the connected reactions of the electron transport chain and the flow of it back through ATP synthase (chemiosmosis)

aerobic

O₂ is required

acetyl CoA

the entry compound for the citric acid cycle, formed by a two carbon fragment of pyruvate attached to a coenzyme, the pyruvate turns into this

cellular respiration

the catabolic pathways of aerobic and anaerobic respiration which break down organic molecules and use an electron transport chain for the production of ATP

ATP synthase

an H+ gradient set up by the electron transport chain, it allows the protons to flow through ATP synthase, it synthesizes ATP and it uses facilitated diffusion

oxidation

the loss of electrons from a substance involved in a redox reaction (LEO)

reduction

the addition of electrons to a substance involved in a redox reaction (GER)

redox reaction

a chemical reaction involving the complete or partial transfer of one or more electrons from one reactant to another

chemiosmosis

the diffusion of ions (in water) across a membrane, it builds up a proton gradient so H+ can flow through the ATP synthase enzyme to build ATP

proton motive force

the potential energy stored in the form of a proton electrochemical gradient, generated by the pumping of hydrogen (H+) ions across a biological membrane during chemiosmosis

proton gradient

the energy stored couples the redox reactions of the electron transport chain to ATP synthase

catabolism

a metabolic pathway that releases energy by breaking down complex molecules to simpler molecules

photosynthesis

the conversion of light energy into chemical energy that is stored in sugars or other organic compounds

non-cyclic photophosphorylation

it forms an N shape and requires 2 photosystems, H₂O, and NADP+. It makes O₂, ATP and NADPH. It’s located in the thylakoid membrane and uses ATP synthase and dehydrogenase.

autotrophs

organisms that produce their own energy, convert energy from sunlight, build organic molecules from CO₂, and synthesizes sugars through photosynthesis

ex: plants, some bacteria

cyclic electron flow

a route of electron flow during the light reactions of photosynthesis that involves only one photosystem, and produces ATP

heterotrophs

organisms that get energy from eating others, they make energy through respiration

ex: consumers (animals, fungi, some bacteria)

cyclic photophosphorylation

it forms a circle and only requires one photosystem and ADP to to make ATP, it’s located in the thykaloid membrane and only uses the enzyme ATP synthase.

rubisco

an enzyme which fixes carbon from the air, it’s the most important and abundant enzyme

transpiration

when plants let out O₂, they also accidentally let out H₂O

chlorophyll

a green pigment embedded in the thykaloid membrane and arranged in a “photosystem”, it’s the main worker

chlorophyll a

a photosynthetic pigment that participates directly in the light reactions which convert solar energy to chemical energy

chlorophyll b

an accessory photosynthetic pigment that transfers energy to chlorophyll a

absorption spectrum

the range of a pigments ability to absorb various wavelengths of light

stomata

a microscopic pore surrounded by guard cells in the epidermis of leaves and stems that allows gas exchange between the environment and the interior of the plant

stroma

the dense fluid within the chloroplast surrounding the thylakoid membrane and containing ribosomes and DNA, it’s involved in the synthesis of organic molecules from CO₂ and H₂O

photorespiration

the breaking of the sugars instead of building the sugars, it’s the oxidation of RuBP and it reduces the production of phtotsynthesis

light reactions

the first of two major stages in photosynthesis, these reactions which occur in the thylakoid membrane convert solar energy to chemical energy (ATP and NADH)

calvin cycle

the second of two major stages in photosynthesis, involving carbon fixation, reduction, and regeneration, it uses the enzyme rubisco

carbon fixation

the initial incorporation of carbon from CO₂ into an organic compound

when rubisco take 3 CO₂’s and adds them to 3 5C molecules (RuBP) that are already in the calvin cycle

NADP+

the oxidized form of nicotinamide adenine dinucleotide phosphate, an electron carrier that can accept electrons, it’s used in plants

NADPH

the reduced form of nicotinamide adenine dinucleotide phosphate that temporarily stored energized electrons produced during the light reactions, it’s in plants

photophosphorylation

the process of generating ATP from ADP and phosphate by means of chemiosmosis, using a proton motive force generated across the thylakoid membrane

photosystem I

a light capturing unit in the chloroplast’s thylakoid membrane, it has two molecules of P700 chlorophyll a at it’s reaction center

photosystem II

a light capturing unit in the thylakoid membrane, it has two molecules of P680 chlorophyll a at it’s reaction center

thylakoid membrane

the flattened membranous sac inside the cloroplast, it’s where light reactions happen

accessory pigments

the other types of plant pigment that don’t include chlorophyll, these pigments create the reds, oranges, and yellow that appear in the fall

reaction center chlorophyll

a complex of proteins associated with a special pair of chlorophyll a molecules and a primary electron acceptor. Located centrally in the photosystems, this complex triggers the light reactions of photosynthesis. Excited by light energy, the pair of chlorophylls donates an electron to the primary electron acceptor, which passes an electron to the electron transport chain

mesophyll cells

leaf cells that are specialized for photosynthesis. In C₃ and CAM plants, these are located between the upper and lower epidermis; in C₄ plants, they are located between the bundle-sheath cells and the epidermis.

action spectrum

a graph that profiles the relative effectivness of different wavelengths of radiation in driving a particular process

C₃ plant

a plant that uses the Calvin cycle for the initial steps that incorporate CO₂ into organic material, forming a 3 carbon compound as the first stable intermediate

C₄ plant

a plant in which the Calvin cycle is preceded by reactions that incorporate CO₂ into a 4 carbon compound, the end product of which supplies CO₂ for the Calvin cycle

a plant that physically separates carbon fixations from the Calvin cycle, it uses different cells to fix the carbon vs. where the Calvin cycle occurs, it stores carbon in 4C compounds

bundle-sheath cells

in C4 plants, its a type of photosynthetic cell arranged into tightly packed sheaths around veins of a leaf

CAM plant

a plant that uses crassulacean acid metabolism, an adapter for photosynthesis in arid (dry) conditions. In this process, CO₂ entering open stomata during the night is converted to organic acids, which release CO₂ for the Calvin cycle during the day, when stomata are closed

plants that separate carbon fixation from the Calvin cycle by time of day, they fix carbon at night and perform the Calvin cycle during the day

PEP carboxylase

an enzyme that adds CO₂ phosphoenolpyruvate to form oxaloacetate in mesophyll cells of C₄ plants. It acts prior to photosynthesis