Biology Chapter 4 Knowt

study tool for mrs. grays class 😭

Autotrophs

Producers that make their own food.

Heterotrophs

Consumers that depend on other organisms for food.

ATP

Adenosine triphosphate; the currency of cellular energy made of adenine, sugar, and three high-energy, unstable covalent bonds between three phosphate groups.

ATP hydrolysis

The process where ATP is broken down into ADP and phosphate, releasing energy.

ADP

Adenosine diphosphate; can be recharged to ATP by adding back the third phosphate.

Dehydration synthesis

Combining of molecules to form a bond by removing a water molecule.

Hydrolysis

Breaking of a bond by adding water.

Endergonic

A reaction that requires an input of energy, e.g., photosynthesis.

Exergonic

A reaction that releases energy, e.g., cellular respiration.

Photosynthesis

Process of converting light energy into stored chemical energy, represented by the equation: 6 CO2 + 6 H2O + light → C6H12O6 + 6 O2.

Pigments

Special light-absorbing molecules.

Chlorophyll

Primary pigment of photosynthesis that absorbs all wavelengths other than green.

Thylakoids

Flattened sacs in chloroplasts containing photosynthetic chemicals.

Grana

Stacks of thylakoids.

Stroma

Areas between thylakoids.

Lumen

Space inside thylakoid.

Electron transport chain

Series of protein molecules in thylakoid membrane that pass electrons.

Photolysis

Splitting of water molecule to replace electrons in chlorophyll.

Hydrogen ion gradient

Build-up of H+ ions from photolysis inside the thylakoid that drives ATP synthase to produce ATP from ADP.

Light Dependent Reactions

Reactions that convert H2O, NADP+, ADP, and light into O2, NADPH, and ATP.

Photosystem I

Structure where chlorophyll is arranged like an antenna to capture and transmit photon energy to the primary electron acceptor.

NADPH

Produced in the second half of the electron transport chain

Z-scheme

Follows electrons in light reactions

Calvin Cycle

Fixes Carbon from CO2 using ATP and NADPH in the stroma of the chloroplasts

Ribulose bisphosphate

A 5-carbon sugar involved in the Calvin Cycle

Nicotinamide adenine dinucleotide phosphate

NADPH, a product of light reactions

Glyceraldehyde 3-phosphate

G3P, a product of the Calvin Cycle

Calvin Cycle Reactants

ATP + NADPH + CO2 + RuBP

Calvin Cycle Products

G3P (glyceraldehyde 3-phosphate)

Conditions for Photosynthesis

1. Adequate quantities of the right wavelengths of light; 2. CO2; 3. Temperature around 70º F; 4. H2O

C4 Plants

Plants that fix CO2 into a 4-carbon molecule even with stomata closed, e.g., corn, sugar cane

CAM Plants

Plants that open stomata at night and store CO2 as an acid, e.g., jade plant

Chemosynthesis

Process of synthesizing sugars by obtaining energy from inorganic chemicals

Endergonic reaction

A reaction that requires an input of energy

Exergonic reaction

The conversion of ATP to ADP, also known as hydrolysis

RuBP

A 5-carbon molecule that the Calvin Cycle attaches CO2 to

Light wavelengths absorbed by chlorophyll

Everything but green

Photosynthesis formula

6 CO2 + 6 H2O —> C6H12O6 + 6 O2

Location of light dependent reactions

Thylakoid membrane

Concentration gradient of H+ ions

Builds up in the lumen of thylakoid

Products of light reactions

ATP, NADPH, oxygen

Reactants of light independent reactions

ATP, NADPH, CO2