Cell Structure

Nucleus

Nucleus

Controls the cell; contains chromosomes (DNA and proteins) for making proteins.

Nucleolus

Produces ribosomal RNA (rRNA) for ribosomes.

Ribosomes

Involved in protein synthesis; make polypeptides.

Endoplasmic Reticulum (Rough)

Series of tubular channels connected with nuclear envelope, covered with ribosomes.

Endoplasmic Reticulum (Smooth)

No ribosomes; associated with lipid and steroid production.

Vesicle

Small vacuole used to move certain compounds; formed from Golgi apparatus or infoldings of cell membrane.

Golgi Body (Apparatus, Complex)

Series of flattened pancakes; processes, stores, and repackages materials produced within the cell.

Lysosomes

Membrane-covered vesicles of digestive enzymes; digest contents and destroy malfunctioning cell parts.

Vacuoles

Non-living membrane-covered sacs filled with food, water, chemicals, and metabolic wastes.

Mitochondria

Supply energy to cell processes as ATP through aerobic cellular respiration.

Microfilaments

Thin solid fibres of protein that provide a skeletal framework (cytoskeleton).

Microtubules

Larger than microfilaments; cylinder-shaped coiled proteins found in cilia and flagella.

Cilia

Short, hair-like projections involved with cell locomotion.

Flagella

Long, whip-like tails involved with cell locomotion.

Centrioles

Organelles in animal cells that create spindle apparatus in cell division.

Cytoplasm

Gel-like substance between cell and nuclear membrane; holds organelles in place.

Cell Membrane

Fluid mosaic structure of phospholipids, carbohydrates, and proteins; selectively permeable.

Plastids

Organelles only found in plant cells, including Chromoplasts, Leucoplasts, and Chloroplasts.

Cell Wall

Rigid structure made of cellulose surrounding the cell membrane in plant cells.

Differences between Plant and Animal Cells

Plant cells have a cell wall, plastids, and a large central vacuole; animal cells have centrioles.

Eukaryotes

Cells with internal membrane-bound organelles, including animal and plant cells.

Prokaryotes

Cells without internal membrane-bound organelles, such as bacteria.

Light Microscope

Magnifies up to 1000X with resolution of 0.2 um.

Electron Microscope

Magnifies up to 30,000X with resolution of 0.0005 um.

Transmission Electron Microscope (TEM)

Provides X-section view of specimens.

Scanning Electron Microscope (SEM)

Provides 3D images of specimens.

Cell Theory

Cells are the basic units of structure and function; all cells come from pre-existing cells.

Chromoplasts

Plastids that contain pigments (orange/yellow) in plant cells.

Leucoplasts

Plastids responsible for starch storage, mainly in potatoes.

Chloroplasts

Plastids containing chlorophyll; site of photosynthesis.

Stroma

Inner portion of chloroplast, where the Calvin cycle occurs.

Thylakoids

Individual sacks within the grana of chloroplasts.

Cristae

Folded inner membrane of mitochondria; increases surface area.

AEROBIC Cellular Respiration

The process by which cells convert carbohydrates and oxygen into carbon dioxide, water, and ATP.

Polysomes

Free-floating ribosomes in cytoplasm, producing proteins for use inside the cell.

Cytoskeleton

Network of proteins (microfilaments and microtubules) that support the cell shape.

Cell Membrane Structure

Composed of a phospholipid bilayer with embedded proteins and carbohydrates.

Ribosomal RNA (rRNA)

Type of RNA that combines with proteins to form ribosomes.

Cellular Transport

Movement of substances across the cell membrane.

Nuclear Envelope

Double layer membrane surrounding the nucleus, with pores for transport.

Vesicular Transport

Movement of materials in vesicles to be separated from the cytoplasm.

Metabolic Wastes

Byproducts of metabolism that must be eliminated from cells.

Endosymbiosis

Theory that explains the origin of mitochondria and chloroplasts as once independent prokaryotes.

Organelles

Specialized structures within a cell that perform specific functions.

Glycolysis

First step of cellular respiration that occurs in the cytoplasm.

ATP (Adenosine Triphosphate)

Main energy currency of the cell.

Cell Locomotion

Movement of a cell due to cilia or flagella.

Basal Body

Structure at the base of cilia and flagella, anchoring them to the cell.