Cell OrganellesSection 7.3

Cell Wall

Found outside some cell membranes It provides support and protection Made of cellulose

Cell Membrane

Controls what enters and leaves the cell Made of lipids and proteins

Nucleus

Leader of the eukaryotic cell because it contains DNA

Every part of the cell depends on proteins to do its jobs, so by containing the blueprint to make proteins, the nucleus controls the activities of all the organelles

Chromatin

Strands of genetic material spread around the inside of the nucleus

Ribosomes and the Nucleolus

Ribosomes are created inside the nucleolus.

In order for proteins to be made, ribosomes must move from the nucleus to the cytopasm.

Cytoplasm

Fluid filled area within the cell Site of chemical reactions

Nuclear envelope The membrane

surrounding all the nuclear material.

Nucleoplasm-the fluid within the nucleus

Nuclear pores in the envelope allow materials to pass into and out of the nucleus

Endoplasmic Reticulum A transport network of

tubes and channels Sites of chemical

reactions Rough ER- has

ribosomes attached to the tubes

Folded Membranes Folded membranes

add surface area for reactions to take place.

The mitochondria and the chloroplast have many folded membranes

Ribosomes

Ribosomes are the sites for protein synthesis.

Golgi Apparatus

Structure that modifies and packages proteins

Made from pieces of the ER

Vacuoles

Temporary storage sites for food, water, and waste

Very large in the plant cell for water storage and turgor pressure

Lysosomes Membrane bound

structure that contains digestive enzymes.

Lysosomes in a tadpoles tail release their enzymes and destroy the tail cells, so the tail recedes

Processes the need Energy

Reproduction Movement Transportation Digestion Protein production Protein modification

Chloroplast Converts the sun’s

energy into chemical energy during photosynthesis

Plastids

Store pigments and starches in plant cells

Chloroplast- stores chlorophyll (green)

Chromoplast- stores other pigments

Leukoplast-stores starches

leukoplasts

chromoplasts

Mitochondria Releases energy from

food during the process of CELLULAR RESPIRATION

Cytoskeleton Thin, fibrous elements that provide

support for organelles Microtubules- thin, hollow cylinders

made of protein Microfilments - thin, solid protein

fibers

Cytoskeleton

Cilia and Flagella Cilia- tiny hair-like projections used in cell

movement Flagella- whip-like or tail-like appendage

used in cell movement

Prokaryote vs. Eukaryote Prokaryote Have cell wall Have cell membrane Have ribosomes Have a circular chromosome Ex: bacteria

Eukaryote Well defined nucleus Have membrane bound organelles DNA in the form of chromatin or

chromosomes Some have a cell wall Ex: plants, fungi, animals, protists

Eukaryote

Prokaryote

Plants vs. Animals

Plant Contain plastids Have a cell wall Have a large vacuole No centrioles

Animal No plastids No cell wall Small vacuoles Have centrioles that function during cell

division

Cell division in Ascaris megalocephala bivalens, in high optical enlargement, 1901.