Biological Principles - Cell Structure Chapter 4 Flashcards

Vocabulary flashcards created from lecture notes covering cell structures, membrane-bound and non-membrane-bound organelles, the endomembrane system, cytoskeleton, and cell boundaries.

Plasma Membrane

A fundamental structure present in all cells, along with cytoplasm, DNA, and ribosomes.

Cytoplasm

Everything inside of the cell.

Ribosomes

Structures present in many per cell that build proteins and are constructed or made out of proteins and RNA.

Eukaryotic Cells

Cells that additionally have membrane-bound organelles, such as the nucleus.

Nucleus

Typically the most prominent organelle in eukaryotic cells that stores DNA and is bounded by the nuclear envelope.

Nuclear Envelope

A double membrane structure that constitutes the outer layer on the nucleus and controls entry and exit.

Chromatin

A protein-DNA complex in which DNA is packed inside the nucleus.

Mitochondria

Membrane-bound organelles that break down organic molecules and generate ATP, featuring inner membrane folds that increase surface area for reactions, as well as their own DNA and ribosomes.

Peroxisome (Peroxism)

An organelle that serves as the site of lipid and fatty acid breakdown, containing and breaking down dangerous hydrogen peroxide byproducts.

Lysosome

An organelle with a low internal pH that denatures proteins and contains digestive enzymes to break down proteins, old or damaged organelles, large food particles, and foreign material.

Vesicles and Vacuoles

Membrane-bound structures that store and/or transport materials, distinguished by vacuoles being larger than vesicles.

Central Vacuole

A huge organelle found only in plant cells that stores water.

Chloroplasts

Plant-only membrane-bound organelles that perform photosynthesis, featuring inner membrane folds that increase surface area for chemical reactions, as well as their own DNA and ribosomes.

Endomembrane System

A system attached to the nuclear envelope composed of folded sheets of membrane with 3 distinct parts: Rough ER, Smooth ER, and Golgi Apparatus.

Rough Endoplasmic Reticulum (Rough ER)

Membrane sheets with attached ribosomes that give it a rough appearance, where proteins are made and inserted into the system.

Smooth ER

A membrane structure lacking ribosomes where carbohydrates and lipids are made, and which breaks down foreign compounds.

Golgi Apparatus

Part of the endomembrane system that performs additional protein modifications and packages proteins into vesicles to ship them where they are supposed to be.

Centrosome

An animal-only organizing structure consisting of 2 centrioles that organizes microtubules and plays a role in cellular division.

Cell Wall

A rigid external protection and support structure made of polysaccharides, present in plant cells but not in animal cells.

Extracellular Matrix (ECM)

An animal-only alternative to the cell wall made of proteins and carbohydrates that provides flexible external protection and support.

Cytoskeleton

A structure that connects everything within the cytoplasm, consisting of 3 major fiber types: microfilaments, intermediate filaments, and microtubules.

Microfilaments (Actin filaments)

Cytoskeletal fibers that allow the cell to change shape and are involved in muscle contraction.

Intermediate Filaments

Cytoskeletal fibers that provide structural stability.

Microtubules

Cytoskeletal fibers located throughout the cell that connect structures, serve as transport rails for vesicles, and are involved in cell division.

Cilia

Short, optional cellular structures used for swimming, usually present in large numbers on cells that possess them.

Flagella

Optional long, hair-like cellular structures.