3. Biology of the cell

Endomembrane System

System of organelles that modify, package, and transport lipids and proteins.

Glycocalyx

Extracellular coating of cells, not part of endomembrane system.

Vesicular formations

Single membrane-bound sacs involved in transport.

Golgi apparatus

Organelle involved in modifying, sorting, and packaging proteins and lipids.

Endoplasmic Reticulum (ER)

Network of membranes involved in protein synthesis and lipid metabolism.

Chromatin

Complex of DNA and proteins (histones) found in eukaryotic nuclei.

DNA

Deoxyribonucleic acid; genetic material.

Membrane transport

Movement of substances across a cell membrane.

Sodium pump

Active transport protein that pumps Na+ out and K+ into the cell.

Diffusion

Passive movement of substances from high to low concentration.

Semicytosis

Not a recognized term in membrane transport.

Phagocytosis

"Cell eating"; engulfment of large particles by the cell.

Pinocytosis

"Cell drinking"; uptake of fluids and small molecules by the cell.

Xanthophylls

Yellow pigments found in chromoplasts and chloroplasts.

Plastids

Group of plant organelles involved in synthesis and storage of food.

Chloroplasts

Plastids containing chlorophyll, site of photosynthesis.

Leukoplasts

Non-pigmented plastids involved in storage.

Chromoplasts

Plastids containing pigments that give color to fruits and flowers.

Amyloplast

Type of leukoplast that stores starch.

Apoplast

Space outside plasma membrane where water and solutes move freely.

Prokaryotic cell

Cell lacking a true nucleus and membrane-bound organelles.

Cellular wall

Rigid outer layer of plant, fungal, and bacterial cells.

Ribosome

Organelle responsible for protein synthesis.

Cell nucleus

Membrane-bound organelle containing genetic material in eukaryotes.

Thylakoids

Membrane-bound sacs in chloroplasts (and cyanobacteria) where photosynthesis occurs.

Mitochondria

Double-membraned organelle, site of cellular respiration.

Semiautonomous organelles

Organelles (like mitochondria, chloroplasts) with their own DNA and ribosomes.

Vesicle formations

Single-membraned sacs involved in transport within cells.

Generation time

Duration of the cell cycle.

Tonoplast

Single membrane surrounding the central vacuole in plant cells.

Aposition

Thickening of cell walls by adding new layers to the outside.

Intussusception

Growth of cell wall by inserting new material within existing layers.

Mitosis

Indirect division of the nucleus, resulting in two identical daughter nuclei.

Telophase

Final phase of mitosis, chromosomes decondense, nuclear envelopes reform.

Metaphase

Phase of mitosis where chromosomes align at the metaphase plate.

Prophase

First phase of mitosis, chromosomes condense, nuclear envelope breaks down.

Ortophase

Not a recognized phase of mitosis.

Anaphase

Phase of mitosis where sister chromatids separate and move to opposite poles.

Plasmodesma

Channels through plant cell walls connecting adjacent cell cytoplasms.

Nexus (Gap Junctions)

Communicating junctions between animal cells.

Mitochondrial matrix

Innermost compartment of the mitochondrion, contains enzymes for Krebs cycle.

Krebs cycle

Series of chemical reactions in cellular respiration, occurs in mitochondrial matrix.

Glyoxalate cycle enzymes

Enzymes found in glyoxysomes (a type of peroxisome).

Semiautonomous DNA

DNA found in mitochondria and chloroplasts.

Nuclear membrane

Double membrane surrounding the nucleus.

Plasma membrane

Outer boundary of the cell.

Polysomes

Multiple ribosomes attached to a single mRNA molecule.

Desmosomes

Cell junctions that provide strong adhesion.

Gonosomes

Sex chromosomes.

Dictyosomes

Another name for Golgi apparatus, especially in plants.

Microsomes

Fragments of ER membranes.

Post-synthetic preparation of proteins

Modification, sorting, and packaging of proteins after synthesis.

Vacuoles

Membrane-bound sacs in cells for storage and waste removal.

Plant cells

Eukaryotic cells with cell walls, chloroplasts, and large central vacuoles.

Prokaryotic cells

Cells without a true nucleus or membrane-bound organelles.

Animal cells

Eukaryotic cells without cell walls or chloroplasts.

Eukaryotic cells

Cells with a true nucleus and membrane-bound organelles.

Glyoxysomes

Specialized peroxisomes in plants, convert fats to carbohydrates.

Bulb cells

Plant cells found in bulbs, may store lipids.

Root cells

Plant cells in roots, can store lipids.

Direct division of the nucleus

Refers to amitosis (less common, not typical mitosis).

Indirect division of the cell

Refers to mitosis (where nuclear division precedes cell division).

Direct division of the cell

Refers to cytokinesis (cell splitting).

DNA in ribosomes

Ribosomes contain rRNA, not DNA.

Budding

Asexual reproduction where an outgrowth develops into a new organism.

Reduction division

Meiosis, cell division that reduces chromosome number by half.