FLASHCARDS

Thylakoid membrane

Where do the light reactions of photosynthesis occur?

Products of the light reactions

ATP, NADPH, and O₂.

Calvin Cycle

Main purpose is to convert CO₂ into G3P (a sugar) using ATP + NADPH.

Final electron acceptor of light reactions

NADP⁺ which becomes NADPH.

Sources of electrons for Photosystem II

Electrons are provided by the splitting of water (photolysis).

Proton gradient in chloroplasts

Created by the electron transport chain between PSII and PSI.

Enzyme that fixes carbon in the Calvin Cycle

Rubisco.

Inefficiency of Rubisco

It can bind O₂ instead of CO₂, leading to photorespiration.

Photorespiration

A wasteful process where O₂ is fixed instead of CO₂, producing no sugar.

C₄ and CAM plants adaptation

Evolved to prevent photorespiration.

Function of mitosis

Growth, repair, and asexual reproduction; produces 2 identical diploid cells.

Function of meiosis

Produces 4 genetically unique haploid gametes.

Crossing over occurrence

Occurs during Prophase I of meiosis.

Separation of homologous chromosomes

Occurs during Anaphase I.

Separation of sister chromatids

Occurs during Anaphase II (meiosis) and anaphase (mitosis).

Genetic variation in meiosis

Created by crossing over and independent assortment.

Independent assortment phase

Happens during Metaphase I.

Law of Segregation

Alleles separate during gamete formation.

Law of Independent Assortment

Genes on different chromosomes assort independently.

Genotype ratio of a dihybrid cross

9:3:3:1 for AaBb x AaBb.

Testcross

Cross between an unknown dominant genotype and a homozygous recessive.

Example of incomplete dominance

Red and white flowers produce pink flowers.

Example of codominance

AB blood type.

Pleiotropy

One gene influences multiple traits.

Epistasis

One gene masks the effect of another gene.

Polygenic inheritance

Many genes affect one trait, e.g., height or skin color.

Stages of cell signaling

Reception, transduction, and response.

Receptor type for steroid hormones

Intracellular receptors.

Receptor type for peptide hormones

Membrane receptors.

Examples of second messengers

cAMP, Ca²⁺, and IP₃.

Enzyme that produces cAMP

Adenylyl cyclase.

Termination of signal pathway

By phosphatases, signal degradation, or receptor removal.

Location of proton accumulation in chloroplasts

Thylakoid lumen.

Molecule from Calvin cycle that makes glucose

G3P.

CO₂ required to produce 1 G3P

3 CO₂.

Calvin cycle turns needed for 1 glucose

6 CO₂ leads to 2 G3P which forms 1 glucose.

ATP production comparison: chloroplasts vs mitochondria

Chloroplasts convert light energy to ATP; mitochondria convert chemical energy (from glucose) to ATP.