A & P Ch. 3 Cell Structure and Functions Flashcards

Vocabulary flashcards for Cell Structure and Functions

Cell

The basic unit of life, showing characteristics of organization, metabolism, responsiveness, homeostasis, growth, and reproduction.

Plasma membrane

Outer layer of the cell, composed mainly of lipids and proteins, enclosing cell contents and regulating what enters and leaves the cell.

Cytoplasm

Material between the nuclear membrane and plasma membrane, including cytosol and organelles.

Cytosol

Fluid portion of the cytoplasm, containing water, enzymes, nutrients, and other substances.

Organelles

Specialized cell structures that perform different cell functions.

Nucleus

Large organelle of cell, surrounded by a nuclear membrane, containing chromosomes that govern cellular activity.

Channels

Pores in the membrane that allow passage of specific substances, such as ions

Transporters

Proteins that change shape as they shuttle substances, such as glucose, across the membrane

Plasma membrane

Outer layer of the cell; composed mainly of lipids and proteins

Microvilli

Short extensions of the plasma membrane

Nucleus

Large, membrane-bound, dark-staining organelle near the center of the cell

Nucleolus

Small body in the nucleus

Cytoplasm

Colloid that fills the cell from the nuclear membrane to the plasma membrane

Cytosol

The fluid portion of the cytoplasm; contains water, enzymes, nutrients, and other substances

Endoplasmic reticulum (ER)

Network of membranes within the cytoplasm. Rough ER has ribosomes attached to it; smooth ER does not

Ribosomes

Small bodies free in the cytoplasm or attached to the ER; composed of RNA and protein

Golgi apparatus

Layers of membranes

Mitochondria

Large organelles with internal folded membranes

Lysosomes

Small sacs of digestive enzymes

Peroxisomes

Membrane-enclosed organelles containing enzymes

Proteasomes

Barrel-shaped organelles

Vesicles

Small membrane-bound sacs in the cytoplasm

Centrioles

Rod-shaped bodies (usually two) near the nucleus

Cilia

Short, hairlike projections from the cell

Flagellum

Long, whiplike extension from the cell

Diffusion

Movement of particles from an area of higher concentration to an area of lower concentration.

Osmosis

Passive movement of water through aquaporins.

Osmotic pressure

Tendency of a solution to draw water into it.

Isotonic

Solution concentration compared to the cytoplasm: same

Hypotonic

Solution concentration compared to the cytoplasm: less

Hypertonic

Solution concentration compared to the cytoplasm: greater

Filtration

Movement of water and dissolved substances down a pressure gradient.

Active transport

Uses chemical energy from ATP to drive movement against the concentration gradient

Vesicular transport

Uses vesicles and ATP to move substances in and out of cells

Phagocytosis

Process of engulfing large particles by the plasma membrane.

Messenger RNA (mRNA)

RNA that is built on a strand of DNA in the nucleus and transcribes the nucleotide code; moves to cytoplasm and attaches to a ribosome

Ribosomal RNA (rRNA)

RNA with protein that makes up the ribosomes, the sites of protein synthesis in the cytoplasm; involved in the process of translating the genetic message into a protein

Transfer RNA (tRNA)

RNA that works with other forms of RNA to translate the genetic code into protein; each molecule of tRNA carries an amino acid that can be used to build a protein at the ribosome

Transcription

First step of protein synthesis; DNA code is copied into messenger RNA (mRNA)

Translation

Second step of protein synthesis; Messenger RNA (mRNA) is decoded and assembled into long chains of amino acids

Cell division

Increase cell numbers for growth, repair, and reproduction

Mitosis

Produces somatic cells (2n) for growth and repair

Cancer

Genetic mutations may cause uncontrolled cell division (mitosis)

Metastasize

Cells spread, producing cancer

Cystic Fibrosis

inherited disease where Ben cannot synthesize a specific chloride channel protein