EXAM 2 REVIEW

Exam review chapters 4,5,6,10,14

Cell

Basic unit of life; building blocks of all organisms.

Single-celled Organisms

Organisms in which the cell is the complete entity.

Tissues

Groups of interconnected cells with a common function.

Organs

Structures composed of different tissues working together.

Organ Systems

Groups of organs that work collectively to perform complex functions.

Surface Area to Volume Ratio

Important factor limiting cell size; as volume increases, surface area increases more slowly.

Plasma Membrane

Encloses the cell and separates its interior from the external environment.

Cytoplasm

Fluid and organelles located between the plasma membrane and the nucleus.

DNA

Genetic material that contains the instructions for the development and function of living organisms.

Ribosomes

Molecular machines that synthesize proteins.

Prokaryotes

Organisms lacking membrane-enclosed internal compartments, including a nucleus.

Peptidoglycan

Material that most prokaryotic cell walls are made of.

Eukaryotic Cells

Cells that contain various organelles, including a nucleus.

Nucleus

Organelle that contains the cell's genetic material.

Mitochondria

Organelles that convert stored energy into ATP.

Peroxisomes

Organelles involved in the breakdown of fatty acids and detoxification.

Chloroplasts

Organelles responsible for photosynthesis in plant cells.

Central Vacuole

Large organelle in plant cells that regulates water concentrations.

Endomembrane System

Network of membranes involved in lipid and protein transport.

Lysosomes

Organelles that contain digestive enzymes for breaking down biomolecules.

Endoplasmic Reticulum

Network of membranes involved in protein and lipid synthesis.

Golgi Apparatus

Organelle that modifies, sorts, and packages proteins and lipids.

Cytoskeleton

Network of protein fibers that maintains cell shape and facilitates movement.

Extracellular Matrix

Complex network surrounding cells in animals, composed of proteins and carbohydrates.

Intercellular Junctions

Connections between cells that facilitate communication and adhesion.

Endosymbiosis Theory

Explains the origin of certain organelles in eukaryotic cells involving mutualistic relationships with prokaryotes.

Diffusion

Process of moving substances from an area of higher concentration to one of lower concentration.

Osmosis

Diffusion of water across a selectively permeable membrane.

Active Transport

Process that requires energy to move substances against their concentration gradient.

Passive Transport

Movement of substances without the use of cellular energy.

Metabolism

Totality of an organism’s chemical reactions.

Catabolic Pathways

Metabolic pathways that break down complex molecules into simpler ones, releasing energy.

Anabolic Pathways

Metabolic pathways that construct complex molecules from simpler ones, requiring energy.

Potential Energy

Stored energy available for use, such as in chemical bonds.

Kinetic Energy

Energy of movement, such as that of molecules in motion.

Gibbs Free Energy

Amount of usable energy available to do work in a system, defined by ΔG.

Activation Energy (EA)

The initial energy required to start a chemical reaction.

Enzymes

Biological catalysts that speed up chemical reactions by lowering activation energy.

Competitive Inhibition

Type of enzyme inhibition where an inhibitor competes with the substrate for the active site.

Noncompetitive Inhibition

Inhibition where an inhibitor binds to an enzyme at a site other than the active site, changing its shape.

Feedback Inhibition

Regulatory mechanism where the end product of a metabolic pathway inhibits an enzyme involved earlier in the pathway.

Mitosis

Process of nuclear division preceding cell division.

Meiosis

Type of cell division that produces gametes with half the number of chromosomes.

Centromere

Region of a chromosome where sister chromatids are joined.

Genome

Complete set of genetic material in an organism.

Chromatin

Complex of DNA and histones that condenses to form chromosomes.

Histones

Proteins around which DNA winds to form chromatin.

Euchromatin

Less condensed form of chromatin that is actively involved in transcription.

Heterochromatin

Highly condensed inactive form of chromatin, generally transcriptionally silent.

Chromatid

One half of a duplicated chromosome, joined to its sister at the centromere.

Homologous Chromosomes

Chromosome pairs, one from each parent, that are similar in shape and size.

Cyclins

Proteins that regulate the cell cycle by activating cyclin-dependent kinases (Cdks).

Cyclin-Dependent Kinases (Cdks)

Enzymes that, when activated by cyclins, regulate progression through the cell cycle.

Tumor Suppressor Genes

Genes that normally limit cell division; mutations can lead to uncontrolled growth.

Proto-oncogenes

Normal genes that can become oncogenes when mutated, promoting cancer progression.

Benign Tumors

Non-cancerous growths that do not invade surrounding tissues.

Malignant Tumors

Cancerous growths that invade nearby tissues and may metastasize.

Transformation

The process by which external DNA is taken up by a cell, resulting in a genetic change.

Frederick Griffith

Scientist known for demonstrating genetic transformation in bacteria.

DNA Nucleotide

Building block of DNA composed of a phosphate group, a sugar, and a nitrogenous base.

Nitrogenous Bases

Adenine (A), Thymine (T), Cytosine (C), Guanine (G) that pair with one another in DNA.

Key Cancer Genes

Genes such as Ras (oncogene) and p53 (tumor suppressor) involved in cancer development.

Cell Division

Process by which a cell divides to form two daughter cells.

Binary Fission

Type of asexual reproduction in prokaryotes involving replication and splitting.

Phagocytosis

Process by which a cell engulfs large particles or cells.

Pinocytosis

Process by which a cell engulfs small particles and liquids.

Cell Membrane

Semi-permeable membrane that separates the interior of a cell from its external environment.

Lipid Bilayer

Structure of the cell membrane composed of two layers of phospholipids.

Fluid Mosaic Model

Concept that describes the structure of the plasma membrane as a mosaic of diverse protein molecules floating in a fluid lipid bilayer.

Microtubules

Cytoskeletal components involved in structure and transport during cell division.

Centrosomes

Organelles that serve as the main microtubule organizing centers of the cell.

Vesicles

Membrane-bound sacs that transport materials within cells.

Cancer Treatment

Various modalities used to disrupt the proliferation of cancerous cells.

Apoptosis

Programmed cell death that is a crucial process in development and maintaining health.

Gene Regulation

Process by which cells control the expression of genes.

Metabolic Pathway

A linked series of biochemical reactions where the product of one reaction becomes the substrate for the next.

Biochemical Reaction

A chemical process within a living organism.

Energy Transformation

The process of changing energy from one form to another.

Entropy

A measure of disorder or randomness in a system.

Genetic Material

Substance that carries hereditary information in organisms, primarily DNA.

Macromolecules

Large molecules essential for life, including proteins, nucleic acids, carbohydrates, and lipids.

Histone Proteins

Proteins that help package and order DNA into structural units called nucleosomes.

Genetic Transformation

Process by which foreign DNA is introduced into a cell, resulting in genetic change.

Mitosis Phases

Sequential stages of nuclear division including prophase, metaphase, anaphase, and telophase.

Cytokinesis Types

Methods of cytoplasm division during the final stage of cell division; differs in plant and animal cells.

Cancer Cells

Cells that have undergone changes leading to uncontrolled division and growth.

Cell Division Functions

Key reasons for cell division include growth, repair, and reproduction.

Protein Synthesis

The process of creating proteins from amino acids based on genetic information.

Evolution of Mitosis

The historical development of the process of mitosis from earlier methods of cell division.