Chemistry Chapter 9-12

Cell division

The ability of organisms to produce more of their own kind.

Omnis cellula e cellula

Rudolf Virchow's concept that all cells arise from pre-existing cells.

Cell cycle

The series of events that a cell goes through as it grows and divides.

Chromosomes

Structures made of DNA and proteins that contain genetic information.

Mitosis

The division of genetic material in the nucleus of a cell.

Cytokinesis

The division of the cytoplasm of a cell.

Sister chromatids

Joined copies of the original chromosome.

Centromere

The region where sister chromatids are attached most closely to each other.

Somatic cells

Non-reproductive cells that have 23 pairs of chromosomes.

Gametes

Reproductive cells that have half as many chromosomes as somatic cells.

Chromatin

The form of chromosomes when a cell is not dividing.

Prophase

The first stage of mitosis where chromatin fibers condense into discrete chromosomes.

Prometaphase

The stage where the nuclear envelope fragments and microtubules invade the nuclear area.

Metaphase

The stage where chromosomes align at the metaphase plate.

Anaphase

The stage where sister chromatids separate and move towards opposite ends of the cell.

Telophase

The stage where daughter nuclei form and chromosomes become less condensed.

Cleavage furrow

The indentation that forms during cytokinesis in animal cells.

Cell plate

The structure that forms during cytokinesis in plant cells.

Binary fission

The process of cell division in bacteria and archaea.

Evolution of mitosis

The hypothesis that mitosis evolved from simpler prokaryotic mechanisms of cell reproduction.

Hypothesis

Ignores potential intermediate mechanisms used by extinct species

Chromosomes

Structures that carry genetic information in the form of DNA

Cleavage furrow

Indentation that forms during cytokinesis in animal cells, leading to cell division

Cell plate

Structure formed during cytokinesis in plant cells, contributing to cell division

S phase

Stage of the cell cycle where DNA replication occurs and chromosomes consist of two identical chromatids

Tubulin

Protein involved in the formation of microtubules, important for mitotic spindle formation and chromosome separation in eukaryotic cell division

Actin

Protein involved in cytokinesis, aiding in the formation of the cleavage furrow or cell plate

Kinetochore

Protein structure located on the centromere of a chromosome, serving as a connection point for microtubules during cell division

Cell cycle

The series of events that take place in a cell leading to its division and duplication

Cell cycle control system

Set of molecules that regulate the sequential events of the cell cycle

Cyclins

Proteins that fluctuate in concentration throughout the cell cycle and are involved in regulating cell cycle progression

Cyclin-dependent kinases (Cdks)

Kinases that are attached to cyclins to become active and regulate cell cycle events

Cell cycle checkpoints

Points in the cell cycle where stop and go-ahead signals can regulate the progression of the cycle

G1 checkpoint

Checkpoint in the cell cycle where a cell receives a go-ahead signal to complete the cycle and divide

G0 phase

Phase in the cell cycle where cells exit the cycle and do not divide

Cancer cells

Cells that exhibit loss of cell cycle controls and can go on dividing indefinitely

Metastasis

Spread of cancer cells from the original tumor to other parts of the body

Chemotherapy

Treatment for cancer that interferes with specific steps in the cell cycle to inhibit cell division

Benign tumors

Tumors that remain at the original site and can be removed by surgery

Malignant tumors

Tumors that include cells that can spread to new tissues and impair organ functions

Histogram

A graphical representation of data that shows the distribution of cells among different cell cycle phases.

Cell cycle phases

The different stages that a cell goes through during its life cycle, including G1, S, G2, and M phases.

Treated sample

A sample of cells that has been subjected to a specific treatment or intervention.

Stem cell-derived inhibitor

A substance derived from stem cells that can halt or slow down the progression of the cell cycle in cancer cells.

G1, S, and G2 phases

The three phases of the cell cycle where DNA replication, growth, and preparation for cell division occur.

Mitotic spindle

A structure made up of microtubules that controls the movement of chromosomes during mitosis.

Cyclin-dependent kinases (CDKs)

Enzymes that are activated by the protein MpF and play a crucial role in regulating the cell cycle.

Receptor tyrosine kinases

Proteins that trigger cell division by activating signaling pathways involved in cell cycle progression.

Interdisciplinary collaboration

Collaboration between different scientific disciplines to gain a comprehensive understanding of cancer and develop effective treatments.

Model organisms

Organisms, such as fruit flies, that are used in scientific research to study biological processes and diseases like cancer.

Cytokinesis

The process of dividing the cytoplasm of a cell after mitosis, resulting in the formation of two daughter cells.

Binary fission

The process of cell division in bacteria, where the chromosome replicates and the daughter chromosomes move apart.

Cell cycle control system

A molecular system that regulates the progression of the cell cycle, ensuring proper cell division.

Checkpoints

Specific points in the cell cycle where the progression is halted until certain conditions are met.

Density-dependent inhibition

The phenomenon where cells stop dividing when they become too crowded, preventing overgrowth.

Anchorage dependence

The requirement for cells to be attached to a surface in order to divide.

Cancer cells

Cells that have lost the ability to regulate their cell cycle and divide uncontrollably, forming tumors.

Metastasis

The spread of cancer cells from the primary tumor to other parts of the body, forming secondary tumors.

Cell plate

A structure that forms during cytokinesis in plant cells and eventually develops into a new cell wall.

Genetically identical daughter cells

The result of most cell divisions, where the two daughter cells have the same genetic material as the parent cell.

Photosynthesis

The process by which plants, algae, and some bacteria convert light energy into chemical energy in the form of sugars.

Cellular Respiration

The metabolic process by which cells convert glucose and oxygen into energy, carbon dioxide, and water.

Chloroplast

The organelle in plant cells where photosynthesis takes place, containing chlorophyll and thylakoids.

Light Reactions

The first stage of photosynthesis that converts solar energy into chemical energy (ATP and NADPH) and produces oxygen as a byproduct.

Calvin Cycle

The second stage of photosynthesis that uses ATP and NADPH to convert carbon dioxide into glucose.

Autotrophs

Organisms that can produce their own food through photosynthesis or chemosynthesis, such as plants and some bacteria.

Heterotrophs

Organisms that obtain organic material by consuming other organisms, such as animals and fungi.

Stomata

Small openings on the surface of leaves that allow for gas exchange, enabling the intake of carbon dioxide and the release of oxygen.

Thylakoids

Membrane-bound structures within chloroplasts where the light reactions of photosynthesis occur.

Chlorophyll

The green pigment in plants that absorbs light energy for photosynthesis, primarily in the blue and red wavelengths.

NADPH

An electron carrier produced in the light reactions that provides reducing power for the Calvin cycle.

ATP

The energy currency of the cell, produced during the light reactions and used in the Calvin cycle.

Rubisco

The enzyme that catalyzes the first step of the Calvin cycle, facilitating the fixation of carbon dioxide.

G3P

A three-carbon sugar produced in the Calvin cycle that can be used to form glucose and other carbohydrates.

Photorespiration

A process that occurs when rubisco binds to oxygen instead of carbon dioxide, leading to a decrease in photosynthetic efficiency.

C4 and CAM Pathways

Alternative photosynthetic pathways that some plants use to minimize photorespiration and maximize carbon fixation in hot, dry environments.

Photosynthesis

The process by which green plants and some other organisms use sunlight to synthesize foods with the help of chlorophyll, converting carbon dioxide and water into glucose and oxygen.

Light-dependent reactions

Reactions that occur in the thylakoid membrane of chloroplasts during photosynthesis. They require light energy to convert ADP and NADP+ into ATP and NADPH, respectively. These reactions also produce oxygen as a byproduct.

Light-independent reactions (Calvin cycle)

The series of chemical reactions in photosynthesis that convert carbon dioxide into glucose molecules. It occurs in the stroma of chloroplasts and does not require light energy. The cycle involves three main steps: carbon fixation, reduction, and regeneration of the starting molecule.

Carbon fixation

The process of incorporating carbon dioxide into organic compounds during the Calvin cycle of photosynthesis.

Factors Affecting Photosynthesis

Various environmental conditions, including light intensity, temperature, carbon dioxide concentration, and water availability, that influence the rate of photosynthesis in plants.

Production of oxygen

One of the significant outcomes of photosynthesis, where oxygen is released as a byproduct during the light-dependent reactions.

Leaf adaptations

The specialized adaptations of leaves, such as their shape, size, and arrangement, that optimize the absorption of sunlight for photosynthesis.

Chloroplast distribution

The strategic arrangement of chloroplasts within plant cells to maximize exposure to light for efficient photosynthesis.

Stomatal control

The regulation of stomatal openings in plant leaves to control the exchange of gases, including carbon dioxide and oxygen, for optimal photosynthesis.

Cyanobacteria

Photosynthetic prokaryotic organisms that can carry out photosynthesis similar to plants and algae, playing a crucial role in Earth's ecosystems.

Photon

A packet of light.

Chlorophyll

The light-absorbing green-coloured pigment that begins the process of photosynthesis.

Chloroplast

A membrane-bound organelle in green plant and algal cells that carries out photosynthesis.

Stroma

The protein-rich semiliquid material in the interior of a chloroplast.

Thylakoid

A disk-shaped sac in the stroma of a chloroplast.

Grana

Stacks of tylakoids.

Lamellae

Groups of unstacked thylakoids between grana.

Thylakoid Membrane

The photosynthetic membrane within a chloroplast that contains light gathering pigment molecules and electron transport chains.

Thylakoid Lumen

A fluid-filled interior space enclosed by the thylakoid membrane.

ATP

A molecule containing three high energy phosphate bonds that acts as the primary energy-transferring molecule in a living organism.

ADP

A molecule containing two high-energy phosphate bonds that may be formed by breaking one of the phosphate bonds in ATP.

NADP+

A compound that accepts one hydrogen atom and two electrons forming NADPH; it is an electron acceptor.

NADPH

A compound that donates one hydrogen aton and two electrons to another molecule, to reform NADP+; it is an electron donor.

Light-dependent reactions

reactions of photosynthesis that use energy from light to produce ATP and NADPH