MCDB 1A Summer Lock-In Midterm 2

free energy

energy that can do work

Gproducts - Greactants

equation for Delta G

metabolism

totality of organism’s chemical reactions

anabolism

building, energy consuming

catabolism

breaking down, energy releasing

exergonic

release of energy (delta G is negative)

hydrolysis

catabolism needing water added

endergonic

require input of energy (delta G is positive)

phosphorylation

The addition of a phosphate group to a molecule — often used to activate or energize it.

cellular respiration

A process that converts glucose and oxygen into ATP, carbon dioxide, and water.

mitochondria

The organelle where most of cellular respiration occurs; known as the powerhouse of the cell.

glycolysis

First step of cellular respiration; occurs in the cytoplasm and breaks glucose into 2 pyruvate molecules, producing 2 ATP and 2 NADH.

pyruvate

A 3-carbon molecule produced from glycolysis; used in the next stages of respiration.

Krebs Cycle

Second step of aerobic respiration; occurs in the mitochondrial matrix, produces CO₂, ATP, NADH, and FADH₂.

NADH / FADH₂

High-energy electron carriers used in the electron transport chain to help produce ATP.

Electron Transport Chain

Final stage of cellular respiration; uses electrons from NADH and FADH₂ to generate a proton gradient for ATP production.

chemiosmosis

Movement of H⁺ ions across the inner mitochondrial membrane to drive ATP synthesis via ATP synthase.

ATP synthase

An enzyme that uses the flow of protons to convert ADP + Pi into ATP.

aerobic respiration

Cellular respiration that requires oxygen; produces up to ~36–38 ATP per glucose.

anaerobic respiration

Occurs without oxygen; includes glycolysis followed by fermentation.

fermentation

A process that regenerates NAD⁺ so glycolysis can continue; produces lactic acid or alcohol depending on the organism.

lactic acid fermentation

Occurs in muscle cells when oxygen is low; converts pyruvate into lactic acid and regenerates NAD⁺.

alcoholic fermentation

Occurs in yeast; converts pyruvate into ethanol and CO₂, regenerating NAD⁺.

glucose

A 6-carbon sugar that is the main fuel molecule for cellular respiration.

oxygen

The final electron acceptor in the electron transport chain; combines with electrons and protons to form water.

metabolism

All chemical reactions in a cell, including those that build molecules (anabolism) and break them down for energy (catabolism).

reaction rate

The speed at which reactants are converted into products; affected by temperature, enzyme presence, substrate concentration, and pH.

protease cleavage

The breaking of peptide bonds in proteins by protease enzymes; helps activate or degrade proteins.

oxidation

The loss of electrons or hydrogen; often associated with a gain of oxygen.

reduction

The gain of electrons or hydrogen; often associated with a loss of oxygen.

oxidizing agent

The molecule that gains electrons (gets reduced) by taking them from another molecule.

reducing agent

The molecule that loses electrons (gets oxidized) by giving them to another molecule.

redox reaction

A chemical reaction involving the transfer of electrons; includes both oxidation and reduction.

Glycolysis inputs

Glucose, 2 ATP, 2 NAD⁺

glycolysis outputs

2 pyruvate, 4 ATP (net 2 ATP), 2 NADH

cytoplasm

where glycolysis occurs

glycolysis

breaks glucose into pyruvate and begins the energy extraction process.

pyruvate oxidation inputs

2 pyruvate, 2 NAD⁺, Coenzyme A

pyruvate oxidation outputs

2 acetyl-CoA, 2 CO₂, 2 NADH

mitochondrial matrix

where Pyruvate Oxidation occurs

pyruvate oxidation

converts pyruvate into acetyl-CoA for entry into the citric acid cycle.

citric acid cycle inputs

2 acetyl-CoA, 6 NAD⁺, 2 FAD, 2 ADP

citric acid cycle outputs

4 CO₂, 6 NADH, 2 FADH₂, 2 ATP

mitochondrial matrix

where Citric Acid Cycle occurs

citric acid cycle

completes glucose breakdown and loads up electron carriers.

electron transport chain inputs

NADH, FADH₂, O₂

electron transport chain outputs

H₂O, ~32-34 ATP

inner mitochondrial membrane

where ETC occurs

Electron transport chain

transfers electrons to oxygen and powers ATP synthase via proton gradient.

fermentation

Regenerates NAD⁺ so glycolysis can continue in the absence of oxygen.

lactic acid fermentation

Converts pyruvate to lactic acid; occurs in muscle cells under low oxygen conditions.

alcoholic fermantation

Converts pyruvate to ethanol and CO₂; occurs in yeast.

NADH

what NAD⁺ is reduced to (gains electrons)

NAD+

what NADH is oxidized back to during ETC or fermentation.

FADH2

what FAD is reduced to in the Krebs cycle

Electron Transport Chain

where FADH₂ donates electrons to

oxygen

Final electron acceptor in the ETC; combines with electrons and protons to form water.

magnification

The process of enlarging the apparent size of an object using lenses or digital tools.

resolution

The ability to clearly distinguish two close objects as separate; higher resolution = more detail.

contrast

The difference in light or color between structures; improves visibility of components under a microscope.

prokaryotic cell

A small, simple cell with no nucleus or membrane-bound organelles; includes bacteria and archaea.

eukaryotic cell

A larger, complex cell with a true nucleus and membrane-bound organelles; includes plants, animals, fungi, and protists.

prokaryotic cell

plasma membrane, cell wall, nucleoid (DNA), ribosomes, and sometimes flagella or pili.

eukaryotic cell

nucleus, endoplasmic reticulum, Golgi apparatus, mitochondria, lysosomes, and cytoskeleton.

nucleoid

The region in a prokaryotic cell where the DNA is located; not membrane-bound.

harder

Larger cells have a lower surface area-to-volume ratio, does this make it harder or easier to transport materials efficiently.

high

do cells need a high or low ratio to move materials in/out quickly enough to survive.

plasma membrane

A phospholipid bilayer that surrounds the cell and controls what enters and exits in prokaryotes

cell wall

A rigid outer layer (made of peptidoglycan in bacteria) that provides protection and shape in prokaryotes

gram-positive bacteria

Bacteria with a thick peptidoglycan layer and no outer membrane; stains purple in Gram stain.

gram-negative bacteria

Bacteria with a thin peptidoglycan layer and an outer membrane; stains pink/red in Gram stain.

peptidoglycan

A mesh-like polymer of sugars and amino acids that forms the bacterial cell wall.

outer membrane

Found in Gram-negative bacteria; provides an additional barrier and contains lipopolysaccharides (LPS) in bacteria

Lipopolysaccharide (LPS)

A molecule in the outer membrane of Gram-negative bacteria; often triggers immune responses.

flagella

Long, whip-like structures used by some cells (including prokaryotes) for movement.

pili

Short, hair-like structures on prokaryotes used for attachment or DNA exchange (conjugation). (fimbrae)

prokaryote

A simple, single-celled organism with no nucleus or membrane-bound organelles; includes bacteria and archaea.

eukaryote

A complex cell with a true nucleus and many membrane-bound organelles; found in animals, plants, fungi, and protists.

prokaryote

lack a nucleus and organelles

eukaryote

have a nucleus and complex internal compartmentalization.

organelle

A specialized structure within a eukaryotic cell that performs a specific function (like a tiny organ inside the cell).

organelle

compartmentalize functions like energy production, waste breakdown, and protein synthesis, which is essential for large, multicellular organisms.

nucleus

The control center of the cell; stores DNA and coordinates cell activities like growth, metabolism, and reproduction.

nucleus

Contains nuclear envelope (double membrane), nuclear pores, nucleoplasm, chromatin, and the nucleolus.

nucleolus

A dense region inside the nucleus where ribosomal RNA (rRNA) is made and ribosomes are assembled.

nuclear envelope

A double membrane that encloses the nucleus and has pores to allow material exchange between the nucleus and cytoplasm.

nuclear pores

Openings in the nuclear envelope that allow the movement of RNA and other molecules in and out of the nucleus.

endosymbiotic

Theory that mitochondria and chloroplasts originated as free-living prokaryotes that were engulfed by ancestral eukaryotic cells.

endosymbiosis

Mitochondria and chloroplasts have their own DNA, double membranes, and reproduce similarly to bacteria.

mitochondria

Organelle that converts food into ATP through aerobic respiration; known as the “powerhouse of the cell.”

chloroplast

Organelle found in plant cells; performs photosynthesis by converting sunlight into chemical energy (glucose).

symbiosis

A close relationship between two organisms; in endosymbiosis, both the host and the engulfed cell benefited.

multicellular organism

An organism made of many specialized cells that work together, relying on organelles to coordinate complex functions.

cytoskeleton

A dynamic network of protein filaments in the cytoplasm that provides structure, shape, and movement for the cell.

microfilaments

Thin filaments made of actin monomers; involved in cell shape, movement, and muscle contraction.

intermediate filaments

Rope-like filaments that provide mechanical strength; made of proteins like keratin and lamin.

microtubules

Hollow tubes made of tubulin dimers (α and β); provide tracks for motor proteins and are essential for cell division.

plus

Tubulin dimers add which end

minus

tubilin disassembly often happens at the which end.

actin polymerization

Actin monomers (G-actin) assemble into filaments (F-actin); important for dynamic changes in cell shape.