Transcript PPT
Cell Structure & Function Sections 7-2 and 7-3 Eukaryote vs. Prokaryote eukaryotes: organisms whose cells contain a nucleus prokaryotes: organisms whose cells lack a nucleus a tiny area between structure that the nucleus performs a and the cell specialized membrane function in the where the cell organelles are found yes no yes yes yes yes yes no both unicellular plants, animals, fungi, protists bacteria A. Boundary Structures Cell Wall Location: outside the cell membrane Function: helps to protect & support the cell A. Boundary Structures Cell Wall found in cells of plants, algae, and some bacteria made of cellulose and lignin A. Boundary Structures Cell Membrane Function: regulates what enters and leaves the cell. Also aids in protection and support of the cell. Made of lipids with associated proteins and carbohydrates. Structure of the Cell Membrane B. Nucleus organelle that controls the cell’s activities and contains DNA Nuclear envelope (membrane): two membranes that form the boundary around the nucleus B. Nucleus Nucleolus: where ribosomes are made made of RNA and proteins Chromatin: DNA bound to protein Spread throughout the nucleus Chromosomes: Distinct structures in nucleus that contain the genetic info that must be passed to each new generation of cells C. Energy Producing Organelles change the chemical energy stored in food into compounds that are more convenient for the cell to use have a degree of independence from the rest of the cell C. Energy Producing Organelles trap sunlight the energy of and convert it into chemical energy found only in plant cells & algae have a degree of independence from the rest of the cell D. Transport/Homeostasis Ribosomes structures in which proteins are made composed of RNA & protein some are attached to membranes (rough ER); others are free in the cytoplasm D. Transport/Homeostasis Endoplasmic Reticulum (er) complex network of sacs that transport materials in the cell 2 types: smooth er rough er D. Transport/Homeostasis Smooth walls er of the sacs look smooth stores special chemicals and enzymes D. Transport/Homeostasis Rough er involved in synthesis of proteins has ribosomes stuck to surface (make it look “rough”) chemically modifies proteins D. Transport/Homeostasis Golgi looks apparatus (body) like a flattened stack of membranes (pancakes) modifies, collects, packages, & distributes molecules made at one location of the cell and used at another Golgi apparatus D. Transport/Homeostasis Lysosomes contain chemicals & enzymes necessary for digesting certain materials in the cell the “clean-up crew” not in plant cells D. Transport/Homeostasis Vacuoles saclike storage structures store water, salts, proteins, and carbohydrates plants have a large central vacuole to store excess water D. Transport/Homeostasis Plastids store food and pigments 3 examples chloroplasts: store chlorophyll leukoplasts: store starch chromoplasts: store pigment molecules E. Framework Cytoskeleton of filaments and fibers that support cell structure and drive cell movement composed of microtubules and microfilaments variety Cytoskeleton E. Framework Microtubules hollow tubes aid in support and movement Cilia: short, thread-like Flagella: long, whip-like Centrioles Located near the nucleus Help organize cell division Not found in plant cells E. Framework Microfilaments long, thin fibers movement & support movement of cytoplasm