1.3 Part of a Cell

This set covers cellular components including the plasma membrane, cell walls across different organisms, internal organelles like the nucleus and ER, and energy-producing structures like mitochondria and chloroplasts.

Plasma membrane

A semipermeable membrane made of a phospholipid bilayer that provides a barrier to separate the inside of a cell from the external environment.

Phosphate head group

The component of a phospholipid that is attracted to water, contributing to the formation of the bilayer effect.

Lipid tails

The part of the phospholipid that repels water, similar to the way oil separates from water in salad dressing.

Protein channels

Structures oriented in the membrane that allow larger molecules like sugar or charged particles to pass through the semipermeable barrier.

Cell wall

A rigid outer membrane that provides support, tensile strength, turgid pressure, and structure to bacterial, plant, fungal, and algal cells.

Osmotic lysis

The bursting of a cell due to osmotic imbalance, which the cell wall protects against.

Mycoplasma

A small percentage of bacterial cells that lack a cell wall altogether.

Peptidoglycan

The polysaccharide and protein component of bacterial cell walls, which is unique to bacteria and serves as a drug target for antibiotics.

Gram positive

A classification of bacteria identified by having a very thick peptidoglycan cell wall.

Gram negative

A classification of bacteria identified by having a very thin peptidoglycan cell wall.

S layer proteins

Surface layer proteins found in the cell walls of Archaea instead of peptidoglycan.

Cellulose

A long linear polymer made of sugar molecules that is one of the most abundant macromolecules on earth and forms the basis of plant cell walls.

Chitin

A derivative of glucose associated with strength, found in fungal cell walls and the exoskeletons of crustaceans and spiders.

Silica

The material that composes the cell walls of diatoms, a group of microalgae found in water and soil.

Cytoplasm

The compartment contained by the plasma membrane where macromolecules and organelles are located.

Cytosol

The watery gel that suspends organelles and provides a site for many of the cell's chemical reactions.

Nucleus

The cell's command center that houses and protects DNA and inhibits mutagenic chemicals from reaching the genetic material.

Nuclear envelope

A double membrane that creates a compartment to protect the nucleus.

Nuclear pores

Channels within the nuclear envelope that allow large molecules to move between the cytoplasm and the nucleus.

Nucleolus

A darkened area within the nucleus where ribosomal RNA is transcribed and synthesized.

Ribosome

A structure made of ribosomal RNA that carries out protein synthesis; it is not an organelle because it is not surrounded by a membrane.

Rough ER

A portion of the endoplasmic reticulum studded with ribosomes where RNA is translated into proteins.

Smooth ER

A portion of the endoplasmic reticulum where ribosomes are absent and lipids, phospholipids, or steroids are produced.

Golgi complex

A series of flattened membranous sacs called cisternae that act as a distribution or shipping center for the cell.

Lysosomes

The waste disposal system of the cell containing hydrolytic enzymes that function only at an acidic pH.

Autophagy

A term literally meaning 'eat itself,' referring to the process where lysosomes digest a cell's own worn-out organelles or macromolecules.

Mitochondria

The site of cellular respiration which uses oxygen to generate $ATP$ for the cell.

Endosymbiotic theory

The theory that a eukaryotic predecessor cell engulfed a prokaryotic cell, which survived and reproduced to become the mitochondria.

Cristae

The inner folded membrane of the mitochondria that increases surface area for energy production reactions.

Chloroplasts

Organelles found in green plants and algae that carry out photosynthesis using the pigment chlorophyll.

Thylakoids

Membranous sacs inside chloroplasts that stack together to form structures called granum.

Universal Components

Basic components and principles shared by all cells, essential to the building blocks and the dogma of biology.

Plasma Membrane

The outer covering of the cell, providing a barrier between the internal and external environments, comprised of a phospholipid bilayer.

Cytoplasm

The entire compartment within the plasma membrane, including macromolecules and organelles.

Nucleus

The command center of eukaryotic cells, housing and protecting DNA.

Endoplasmic Reticulum (ER)

An interconnected series of membrane-enclosed sacs and tubes; Rough ER is involved in protein synthesis, while Smooth ER is involved in lipid production and nutrient metabolism.

Golgi Complex

The cell's distribution center; modifies and transports macromolecules from the ER.

Lysosomes

The waste disposal system of the cell containing hydrolytic enzymes for digestion.

Mitochondria

Sites of cellular respiration that generate ATP using oxygen.

Chloroplasts

Organelles involved in photosynthesis, found in green plants and algae.

Peptidoglycan

A unique molecule found in bacterial cell walls, composed of polysaccharides and proteins.

Gram-Positive Bacteria

Bacteria with thick peptidoglycan walls that retain specific stains.

Gram-Negative Bacteria

Bacteria with thin peptidoglycan walls.