College Biology

Cell Parts

Nucleus

1. Stores genetic material

2. Surrounded by a nuclear envelope

3. In chromosomes - DNA is organized with proteins to form chromatin

4. Stores Nucleus - makes rRNA + ribosomal subunits

Ribosomes

1. The site of protein synthesis

2. Made of Ribosomal RNA

l. Free Ribosomes - float in cytosol, produse protiens

ll. Bound Ribosomes - attached to ER, make protiens for export from cell

Endomembrane System

1. series of membranes throughout the cytoplasm

2. divideds cell into compartments where different cellular functions occur

l. Endoplasmic recticulum

ll. Golgi Apparatus

lll. Lysosomes

Rough Endoplasmic Reticulum

1. membranes that create a network of channels throughout the cytoplasm

2. Attachment of ribosomes to the membrane gives a rough appearance

3. Synthesis of proteins to be secreted, sent to lysosomes or plasma membrane

Smooth Endoplasmic Reticulum

1. Relatively few ribosomes attached

2. Functions

l. synthesis of membrane lipids

ll. Calcium Storage

lll. Detoxification of foreign substances

Golgi Apparatus

1. Flattened stacks of interconnected membranes

2. Packaging + distribution of materials to different parts of the cell

3. Synthesis of cell wall componets

Lysosomes

1. Membrane bound vesicles containing digestive enzymes to break down macromolecules

2. destroy cells or foreign matter the the cell has engulfed by phagocytosis

3. Apoptosis - Programmed cell death

Vacuoles

1. membrane bound structures with various functions depending on the cell type

Microbodies

1. membrane bound vesicles

2. contain enzymes

3. not part of the endomembrane system

4. Peroxisomes - contain oxidase to metabolize fatty acids, amino acids.

Mitochondria

1. Powerhouse of the cell

2. found in the cells of most eukaryotes, such as animals, plants and fungi

3. have a double membrane structure

Chloroplasts

type of organelle known as a plastid that conducts photosynthesis mostly in plant and algal cells. Chloroplasts have a high concentration of chlorophyll pigments which capture the energy from sunlight and convert it to chemical energy and release oxygen

Vasicles

an organelle within or outside a cell, consisting of liquid or cytoplasm enclosed by a lipid bilayer. Vesicles form naturally during the processes of secretion, uptake, and the transport of materials within the plasma membrane.

Actin

family of globular multi-functional proteins that form microfilaments in the cytoskeleton, and the thin filaments in muscle fibrils.

Intermediate Filaments

1. most durable tough, fibrous protien - adds strength to cell

Microtubules

1. Structure - consist of alpha and beta tubulin protiens to form a tube - have a plus and minus end

2. Function - Assist in intracellular transport-motor protien

Cell Wall

Found in - Plants, Fungi, and Protists