big bio chapt 4

Nucleus

The cell's control center, encasing the nucleolus and chromosomes.

Golgi Body

Organelles that process and package proteins and lipids for use inside and outside the cell.

Vacuole

A sac in the cell that stores nutrients, water, and waste.

Prokaryote

Unicellular organisms without a nucleus, recycling, producing, and decomposing organic matter.

Eukaryote

Cells or organisms that possess a clearly defined nucleus.

Enzyme

Proteins that speed up and facilitate chemical reactions within an organism.

Chlorophyll

The green pigment in plants responsible for photosynthesis.

Endoplasmic Reticulum

An organelle that processes molecules required for cell function and communication.

Spongy Mesophyll

Mesophyll cells in plant leaves with air spaces that carry out photosynthesis.

Cytoskeleton

A structural framework for the cell, providing shape and organization.

Mitochondria

The powerhouse of the cell that produces ATP, the main energy molecule.

Lysosome

The digestive system of the cell, breaking down materials and obsolete cell parts.

Gene

Information passed from parents to offspring that specifies physical and biological traits.

Chloroplast

Organelles in plant cells responsible for carrying out photosynthesis.

Rough Endoplasmic Reticulum

Processes proteins and is studded with ribosomes for protein synthesis.

Smooth Endoplasmic Reticulum

Responsible for the synthesis of carbohydrates, lipids, and steroid hormones.

Palisade

A layer of densely packed cells in leaves that contain chloroplasts and carry out photosynthesis.

Cells

Humans have about 100 trillion (10^14) cells.

DNA

Deoxyribonucleic acid acts as a set of instructions for building an organism.

Nucleotides

The genome has four nucleotides: Adenine (A), Thymine (T), Guanine (G), Cytosine (C).

Cell Theory

One of the unifying principles of biology asserting that all cells come from pre-existing cells and that living organisms have to contain one or more cells.

Virus

A small infectious agent that can replicate only inside a living cell, usually with a DNA or RNA genome in a protein coat.

Characteristics of Living Organisms

Composed of one or more cells, reproduce using DNA, obtain energy, sense and respond to the environment, maintain internal balance, can evolve.

Plasma Membrane

A phospholipid bilayer that separates a cell from its external environment.

Liposome

Formed when a phospholipid bilayer creates a sphere, acting as a semipermeable barrier. Have specialized jobs for each differenyt one.

Selective Permeability

Allows only some substances to cross the plasma membrane on their own.

Passive Transport

Movement across a membrane without energy, including diffusion and facilitated diffusion.

Active Transport

Movement that requires energy to transport substances against their concentration gradient.

Osmosis

Specific form of diffusion through a plasma membrane, involving the movement of water.

Isotonic

When cells are surrounded by a fluid with the same solute concentration as the cell's interior.

Hypertonic

When cells are surrounded by a fluid with a higher solute concentration than the cell's interior.

Hypotonic

When cells are surrounded by a fluid with a lower solute concentration than the cell's interior.

Vesicle

Packages formed by sections of the cell’s plasma membrane to transport substances.

Exocytosis

Process used to expel substances from the cell.

Endocytosis

Process used to bring external substances into the cell.

Receptor-mediated endocytosis

Process where receptor proteins recognize and bind to specific molecules to take them into the cell.

Phagocytosis

Endocytosis of a large substance, also known as cellular eating.

Pinocytosis

Endocytosis of a liquid, also known as cellular drinking.

Genes

Small instructions, are 5-5000 base pairs of DNA

Genomes

30000 genes

Endosymbiotic Theory

Proto cells(eg mitochondria and chloroplasts), absorbed phagocytosis, prokaryotes