Plants and Humans Notes for Exam 2 Chapter 5: Photosynthesis and Cellular respiration Photosynthesis Sunlight energy is converted into chemical ener

Photosynthesis

The process by which sunlight energy is converted into chemical energy (food) by plants.

Photosynthesis Formula

6CO2 + 6H2O + sunlight 🡪 C6H12O6 + 6O2 (Carbon Dioxide + water 🡪 glucose + oxygen).

Chloroplasts

Organelles in plant cells where photosynthesis occurs; they have two membranes, contain chlorophyll, and have structures like thylakoids, granum, and stroma.

Chlorophyll A

Primary pigment for photosynthesis that absorbs mainly in the red and blue areas of the light spectrum.

Stages of Photosynthesis

The two main stages are the Light-Dependent Stage (Light Reactions) and the Light-Independent Stage (Calvin Cycle).

Light-Dependent Stage

Stage of photosynthesis occurring in the thylakoids, requiring light, where water is split and oxygen is released.

Calvin Cycle

Light-Independent Stage where carbon dioxide is fixed to form sugars using ATP and NADPH produced in the light reactions.

Cellular Respiration

The process of breaking down glucose through chemical reactions to produce cellular energy (ATP).

Cellular Respiration Formula

C6H12O6 + 6O2 🡪 6CO2 + 6H2O + ATP (Glucose + oxygen 🡪 carbon dioxide + water + ATP).

Three Steps of Cellular Respiration

1. Glycolysis, 2. Citric Acid Cycle (Krebs Cycle), 3. Electron Transport Chain.

Mitochondria

Organelles where most cellular respiration occurs; they have two membranes and a highly folded inner membrane.

ATP

Adenosine triphosphate, the cellular energy currency.

Glycolysis

Process where glucose is split in the cytosol, generating 2 pyruvate molecules.

Citric Acid Cycle

Also known as Krebs Cycle, it occurs in the mitochondrial matrix and involves the release of CO2.

Aerobic Cellular Respiration

Cellular respiration that requires oxygen.

Anaerobic Cellular Respiration

Respiration that occurs in the absence of oxygen, including alcoholic and lactic acid fermentation.

Plant Hormones

Chemical messengers that regulate various plant functions.

Auxin

A plant hormone that promotes apical dominance and cell elongation.

Ethylene

A plant hormone involved in the ripening of fruit.

Seed Germination

The process where the embryo takes in water and starts to swell, eventually leading to growth.

Tropic Response

Growth of a plant in response to a stimulus, which can be positive (toward) or negative (away) to the stimulus.

Phototropism

The growth of plants toward light.

Gravitropism

The response of plant roots bending downward toward gravity.

Asexual Reproduction

Reproduction that involves a single parent and produces genetically identical offspring.

Sexual Reproduction

Reproduction involving two parents, resulting in genetic diversity among offspring.

Diploid

A cell with two complete sets of chromosomes (2n).

Haploid

A cell with one complete set of chromosomes (n).

Cell Cycle

The life cycle of a cell from one division to the next, consisting of interphase, nuclear division, and cytokinesis.

Mitosis

A process of nuclear division in body cells associated with asexual reproduction, consisting of PMAT (prophase, metaphase, anaphase, telophase).

Meiosis

A type of nuclear division that decreases the amount of DNA by half, occurs in reproductive cells.

Crossing Over

The exchange of genetic material between homologous chromosomes during prophase I of meiosis.

Climacteric Fruits

Fruits that continue to ripen after being harvested due to ethylene production.

Non-Climacteric Fruits

Fruits that must stay attached to the plant to ripen, with little to no ethylene involvement.