An Introduction to Human Cells and Tissues

A comprehensive vocabulary flashcard set reviewing cell organelles, membrane transport, protein synthesis, cell division, tissue categories, and homeostatic regulation.

Fluid Mosaic Model

A model of the plasma membrane where membrane lipids move laterally (fluid) and membrane proteins are interspersed among the phospholipids (mosaic).

Phospholipid Bilayer

The core lipid structure of the plasma membrane, composed of hydrophilic ionic heads pointing outwards and hydrophobic fatty-acid tails pointing inwards.

Anchoring Proteins

Membrane proteins attached to inside or outside cell structures that act as stabilisers.

Recognition Proteins

Glycoproteins in the plasma membrane that label cells as normal or abnormal.

Carrier Proteins

Membrane proteins that transport specific solutes across the plasma membrane.

Channel Proteins

Membrane proteins that regulate the flow of water and solutes across the plasma membrane.

Primary Cilia

Long extensions of the plasma membrane containing microtubules that act as sensors.

Motile Cilia

Long extensions of the plasma membrane containing microtubules that move materials over cell surfaces.

Microvilli

Extensions of the plasma membrane containing microfilaments that increase surface area to facilitate absorption of extracellular materials.

Cytosol

The fluid component of cytoplasm containing high potassium ions, low sodium ions, high proteins, high carbohydrates, and low amino acid and fat waste products.

Nucleoplasm

The fluid inside the cell nucleus containing ions, enzymes, nucleotides, and RNA.

Nucleolus

A nuclear region made of RNA, enzymes, and histones that synthesizes ribosomal RNA and ribosomal subunits.

Centrioles

Structures composed of 9 microtubule triplets in a $9 + 0$ array that direct the movement of chromosomes during cell division and organize the cytoskeleton.

Smooth ER

Endoplasmic reticulum without ribosomes attached, responsible for the synthesis of lipids and carbohydrates.

Rough ER

Endoplasmic reticulum with ribosomes attached, responsible for the synthesis of proteins.

Golgi Apparatus

Organelle consisting of stacks of flattened membranes containing chambers that stores, alters, and packages secretory products and lysosomal enzymes.

Mitochondria

Double-membraned organelles with inner membrane folds that produce 95% of the ATP required by the cell.

Peroxisomes

Vesicles containing degradative enzymes that perform catabolism of fats and other organic compounds and neutralization of toxic material.

Lysosomes

Vesicles containing digestive enzymes responsible for intracellular removal of damaged organelles or pathogens.

Chromatin

The uncoiled, threadlike form of DNA combined with histones present in non-dividing cell nuclei.

Transcription

The process where transcription factors and RNA polymerase bind to the TATA promoter region to synthesize complementary mRNA from a DNA template strand.

Translation

The process where a ribosome moves along mRNA, allowing tRNA to bind to codons with matching anticodons to produce a polypeptide chain.

Meiosis

A form of cell division occurring in ovaries and testes for the production of gametes.

Loose Connective Tissue

Connective tissue proper characterized by high ground substance and low fibers, including areolar, adipose, and reticular tissues.

Dense Connective Tissue

Connective tissue proper characterized by low ground substance and high fibers, including dense regular, dense irregular, and elastic tissue.

Neuron

A specialized nerve cell responsible for performing electrical communication rapidly within neural tissue.

Neuroglia

Supporting cells in neural tissue that repair and supply nutrients to neurons.

Negative Feedback

A homeostatic regulatory mechanism in which the effector's response negates the original stimulus to return the body to normal conditions.

Positive Feedback

A homeostatic regulatory mechanism in which the effector's response increases the change of the stimulus, moving the body away from homeostasis.