Cell Organelles and their Functions - Ap Bio

For AP Biology

Nucleus

Function - Control Center of the cell, housing genetic material (DNA) and coordinating activities

Nuclear Pores

Small openings in the nuclear envelope that regulate the transport of molecules in and out of the nucleus

Chromatin

A complex of DNA and proteins found in the nucleus that condenses to form chromosomes during cell division

Nucleolus

A dense region within the nucleus where ribosomal RNA (rRNA) is synthesized and ribosome assembly begins.

Ribosomes

Function - Protein synthesis, composed of rRNA and protein

Free Ribosomes

Ribosomes that float freely in the cytosol, synthesizing proteins that function within the cytoplasm.

Bound Ribosomes

Ribosomes attached to the endoplasmic reticulum, synthesizing proteins destined for secretion or for use in membranes.

Endomembrane System

A network of membranes that includes the nuclear envelope, endoplasmic reticulum, Golgi apparatus, lysosomes, and vesicles, vacuoles, and plasma membrane. Involved in the synthesis, modification, and transport of proteins and lipids.

Rough Endoplasmic Reticulum

A type of endoplasmic reticulum that is studded with ribosomes, involved in protein synthesis and processing. Sends transport vesicles to Golgi

Smooth Endoplasmic Retiticulum

A type of endoplasmic reticulum that lacks ribosomes, involved in lipid synthesis, detoxification, and calcium ion storage.

Golgi Apparatus

A membrane-bound organelle that modifies, sorts, and packages proteins and lipids for secretion or delivery to other organelles. Produces Lysosomes. Cis face - Receives vesicles, Trans face - Ships vesicles

Lysosomes

Intracellular digestion; recycle cell’s materials; programmed cell death (apoptosis)

Vacuoles

Membrane-bound sacs that store nutrients, waste products, and help maintain turgor pressure in plant cells. Plants - large central, Animal - multiple small

Mitochondria

Organelles that produce ATP through cellular respiration, often referred to as the "powerhouses" of the cell. They have a double membrane and contain their own DNA.

Cristae

Folded inner membrane of mitochondria that increases surface area for ATP production.

Matrix

The fluid-filled space within the mitochondria where the Krebs cycle occurs, containing enzymes and mitochondrial DNA.

ATP

Adenosine triphosphate, the primary energy carrier in all living organisms, used in various cellular processes.

Chloroplasts

Organelles found in plant cells that conduct photosynthesis, converting light energy into chemical energy. Double membrane enclosed structure containing thylakoids (disks in stacks) and stroma (fluid). Chloroplasts also contain pigments like chlorophyll, which absorb light energy for photosynthesis.

Endosymbiont theory

The theory that explains the origin of eukaryotic cells, suggesting that they evolved from symbiotic relationships between different species of prokaryotes. Mitochondria and chloroplasts are believed to have originated this way, having their own DNA and double membranes.

Peroxisomes

and other reactive oxygen species, playing a role in lipid metabolism and the detoxification of harmful substances. Breaks down fatty acid; detox alcohol. Production of hydrogren peroxide

Cytoskeleton

A network of protein filaments and tubules that provide structural support, shape, and organization to the cell. It plays a crucial role in cell movement, division, and intracellular transport.

Microtubuls

Chromosome movement in cell division

Microfilaments

Cell division, change in cell shape, cell motility

Intermediate filaments

Anchorage of nucleus and some other organelles

Centrosomes

Region from which microtubules grow, in Animal cells

Cilia

Short and numerous tails; locomotion or move fluids

Flagella

Long and few tails; propel through water

Cell Wall

Protect plants, maintain shape, composed of cellulose

Plamodersmata

Channels between cells to allow passage of molecules from cell to cell

Extracellular Matrix

Outside plasma membrane of animal cells. Composed of glycoproteins, strengthens tissues and transmit external signals to cell

Tight Junctions

Two cells are fused to form watertight seal.

Desmosomes

Rivets that fasten adjacent cells into strong sheetsGap

Gap Junctions

Channels through which ions, sugar, small molecules can pass