biology 152 chap 4 #10

Nucleolus

A darkly staining area within the nucleus that aggregates the ribosomal RNA with associated proteins to assemble the ribosomal subunits that are then transported out through the pores and the nuclear envelope to the cytoplasm.

peroxisomes

Small, round organelles enclosed by single membranes that carry out oxidation reactions that break down fatty acids and amino acids. They also detoxify many poisons that may enter the body. Peroxisomes also detoxify alcohol. Glyoxysomes, which are specialized peroxisomes in plants, are responsible for converting stored fats into sugars. Plant cells contain many different types of peroxisomes that play a role in metabolism, pathogene defense, and stress response, to mention a few.

vacuoles

membrane- bound sacs that function in storage and transport. Vacuole's membrane does not fuse with the membranes of other cellular components, unlike vesicles. Some agents such as enzymes within plant vacuoles break down macromolecules.

Mitochondria

often called the cells "powerhouses" or "energy factories" because they are responsible for making adenosine triphosphate (ATP). In mitochondria cellular respiration uses oxygen and produces carbon dioxide as a waste product. Muscle cells have a very high concentration of mitochondria that produce ATP. Mitochondria are oval-shaped, double membrane organelles that have their own ribosomes and DNA.

Chloroplasts

plant cell organelles that carry out photosynthesis, chloroplasts have their own DNA and ribosomes, but have entirely different functions. Like mitochondria, chloroplasts have outer and inner membranes, but within the space enclosed by a chloroplast's inner membrane is a set of interconnected and stacked fluid-filled membrane sacs we call thylakoids. chloroplast contain a green pigment, which captures the light energy that drives the reactions of photosynthesis. Like plant cells, photosynthetic protists also have chloroplasts.

Ribosomes

the cellular structures responsible for protein synthesis, they may be attached to the plasma membrane's cytoplasmic side or the endoplasmic reticulum's cytoplasmic side and the nuclear envelope's outer membrane. Ribosomes are large proteins and RNA complexes, they receive their orders for protein synthesis from the nucleus where DNA transcribes into messenger RNA (mRNA)

Lysosomes

there roles consist digetsive component and organelle- recycling facility of animal cells, they also use their hydrolytic enzymes to destroy pathogens that might enter the cell. lysosomes are part of the endomembrane system

Golgi apparatus

a series of flattened membranes where sorting, tagging, packaging, and distributing lipids and proteins takes place.

Endoplasmic Reticulum

a series of interconnected membranous sacs and tubules that collectively modifies proteins and synthesizes lipids. Its membrane is a phospholipid bilayer embedded with proteins and is continuous with the nuclear envelope. it has two separate areas of ER: the rough ER and the smooth ER. Rough ER is the ribosomes attached to its cytoplasmic surface give it a studded appearance when viewing it through an electron microscope, while Smooth ER has few or no ribosomes on its cytoplasmic surface.

Nucleus

the most prominent organelle in a cell, houses the cell's DNA and directs the synthesis of ribosomes and proteins. The nucleus stores chromatin in a gel-like substance called the nucleoplasm. The nucleolus is a condensed chromatin region where ribosome synthesis occurs. the nucleus boundary is called the nuclear envelope, it consists of two bilayers an outer an dinner membrane.