Cellular Energetics - Unit 3

2nd law of thermodynamics

states that everything is constantly moving towards disorder/ chaos

Exergonic

A reaction that releases energy and happens spontaneously, helping power many processes in the cell.

Endergonic

A reaction that requires energy and stores energy in molecules like fats.

Energy Coupling

Using energy from ATP in a series of steps to power a larger reaction more efficiently.

Enzymes

Proteins that act as catalysts to speed up reactions without being permanently changed; they work through a specific active site that fits the substrate like a lock and key.

Induced fit model

The enzyme and substrate slightly change shape to fit each other, allowing the reaction to occur.

Common Reaction

Expose the cite to allow the reaction to occur

Anarobic reaction

A reaction that builds molecules and requires energy.

Activation Energy

The energy needed to start a chemical reaction; enzymes lower this energy to make reactions faster and more efficient.

Optimum conditions

The temperature and environment where an enzyme work best; if conditions aren’t right, the enzyme’s shape can change and slow the reaction.

Denature

Changing the shape of the enzyme due to conditions and the enzyme does not work anymore

Inhibitors

Molecules that block an enzyme from working, either by attaching to the active site or changing its shape at an allosteric site.

Competitive inhibitor

A molecule that blocks an enzyme’s active site by competing with the substrate, preventing the reaction.

non competitive inhibitor

A molecule that binds to a different part of the enzyme (not the active site) and changes its shape, preventing the enzyme from working properly.

Adhesion

Property of water that allows water to stick to other surfaces or materials

Cohesion

Property of water that allows water to move by water working with itself

Why water is able to move up the plant

As water goes up the plant, the water potential within the plant continues to decrease

leaves

Where plants receive carbon dioxide from

Roots

Where plants receive water from

stomata

Tiny openings on the underside of leaves that open and close to allow gas exchange—letting carbon dioxide in and oxygen out.

guard cells

control the opening and closing of the stomata and conserve water when needed

Chloroplast

Plant cell organelle where photosynthesis happens. It contains the stroma and thylakoid lumen

chlorophyll a, clorogphyll b, and carotene

Three types of pigments in plants

Pigments

light absorbing molecules in chloroplasts that help with the start of photosynthesis and is essential for the breaking of water in the light dependent reaction

Photon

Particle of light that interacts with the electrons within the chloroplasts to get it move on the thylakoid membrane

Photosystem 2

First portion of the light dependent reaction that is on the thylakoid membrane. The light absorbed goes through a series of reactions and ultimately breaks down water to get the byproducts of photosynthesis.

MnCa

First place where the excited electrons go after absorbing the pigments. When the elections reach the complex, the energy collected from the electron will ultimately break the water into oxygen and hydrogen ions.

Into the thylakoid membrane

Where hydrogen ions go after being broken apart from the water molecule

They go into the thylakoid membrane

Where oxygen go after being broken apart from the water molecule

Cyt complex

Next place where the electrons go to after losing some energy. It is an active pump that pumps hydrogen ions into the thylakoid and uses some of the electron’s energy to allow this pump to function.

Photosystem 1

Electrons go to this system after the CYT complex and gets reenergized there. Here, the NADP+ gets changed to NADPH to move onto the Calvin cycle.

ATP synthase

Works when there is a high H⁺ concentration. Hydrogen ions flow through the protein, causing shape changes that spin the rotor, allowing ADP and phosphate to bind and form ATP.

rotor

In the middle portion of the ATP synthase and makes rotates when there’s a confirmation change.

Phosphorylation

Process of adding a phosphate group to a molecule

Calvin cycle

A cycle that goes through a series of reactions in the chloroplast that makes the end product of G3P for photosynthesis

Carbon fixation

Uses the carbon dioxide that enters the cycle by building the carbon parts together.

Reduction

Happens after carbon fixation and uses ATP as energy to produce ADP and NADP+ to be used again in the light dependent reactions and also creates G3P

Regeneration

Uses G3P to make RuBP to make a larger molecule to be reused in the cycle again.

G3P

End product of photosynthesis

RuBP

A large molecule that is used over and over again in the Calvin cycle. Makes the carbon fixation part of the cycle run more efficiently for the next cycles.

Gluconeogenesis

A series of reactions that uses the product of G3P to make glucose for the organism.

Plants, Bacteria, Protists

What organisms can do photosynthesis

Photosynthesis in bacteria

Uses the walls inside of the prokaryote to act as the thylakoid membrane to perform photosynthesis.

Cynobacteria

A type of bacteria that can perform photosynthesis and benefits the environment by adding nutrients but becomes harmful when it dies because it blocks other organisms from accessing the nutrients they need.

Stromatolites

ancient, layered structures formed by photosynthetic cyanobacteria, which helped oxygenate Earth’s early atmosphere.

Cellular respiration

entire point of this process is to get ATP

glycolysis

happens in the cytoplasm and breaks glucose into pyruvate. It uses 2 ATP but produces 4 ATP overall and uses electron carriers like NADPH.

fermentation

anaerobic process used when oxygen is low or quick energy is needed. Works by using reusing electron carries by emptying electron carriers.

fermentation in bacteria

an anaerobic process that lets them keep making ATP without oxygen by recycling their electron carriers, producing byproducts like lactic acid or alcohol.

fermentation in humans

an anaerobic process that lets muscles keep producing ATP when oxygen is low by recycling electron carriers, creating lactic acid as a byproduct.

Into the mitochondria matrix

Where pyruvate go to after being broken down

Krebs cycle

Cycle that produces as many electrons as possible for the mitochondria to use in the ETC.

Acetyl-CoA

Brakes down pyruvate from the glycolysis cycle and changes it to this by ripping off a carbon

Citric acid

Made after Acetyl-CoA after a series of reactions

End product of krebs cycle

Makes a lot of electrons and 1 atp, but goes through twice because of the 2 pyruvates made from glycolysis.

Restart of the Krebs cycle

Uses the electrons and atp to power the cycle again

Inner mitochondrial membrane

It is where the ETC reactions take places and hold all of the hydrogen ions

Complex 1, 3, 4

Pumps all of the hydrogen ions into the intermembrane space of the mitochondria by using electrons from the krebs cycle

Complex 2

Accepts electrons from Krebs cycle to act as an Uber to the other complex to help power them through a series of reactions.

Hydrogen ions in mitochondria

Once there is a buildup of hydrogen ions in the inner membrane space, it goes through ATP synthase to make ATP