vocab Flashcards
cell?
A cell is the basic structural and functional unit of all living organisms.
cell theory?
All living organisms are composed of one of more cells.
Cells are the basic unit of structure and organization of all living organisms.
Cells arise only from previously existing cells, with cells passing copies of their genetic material on to their daughter cells.
plasma membrane?
A plasma membrane is a special boundary that helps control what enters and leaves the cell.
organelle?
Organelles are specialized structures that perform specific cell functions.
eukaryotic cell?
Eukaryotic cells contain a nucleus and other organelles.
nucleus?
The nucleus is the distinct central organelle that contains the cell’s genetic material.
prokaryotic cell?
Prokaryotic cells are cells without a nucleus or other membrane-bound organelles.
selective permeability?
Plasma membranes have selective permeability, meaning they allow some substances to pass through while keeping others out.
phospholipid bilayer?
The plasma membrane is composed of phospholipid bilayer – two layers of phospholipids are arranged to allow the membrane to exist in a watery environment.
Carbohydrates?
Carbohydrates define the cell’s characteristics
fluid mosaic model?
The fluid mosaic model describes the phospholipids in the bilayer as a “sea” in which other components can float and move around.
Glycoproteins?
carbohydrates (glycogen) attached to proteins
Glycolipids?
carbohydrates attached to lipids
diffusion?
Diffusion is the net movement of particles from an area of high concentration to an area of lower concentration.
dynamic equilibrium?
When diffusion occurs over a long enough time, concentrations will become uniform, and the solution will reach dynamic equilibrium.
facilitated diffusion?
Facilitated diffusion uses transport proteins to move ions and small molecules across the plasma membrane.
osmosis?
Osmosis is the diffusion of water across a selectively permeable membrane.
isotonic solution?
An isotonic solution has the same concentration of water and solutes as the cytoplasm of the cell.
hypotonic solution?
A hypotonic solution has a lower concentration of solutes than the cytoplasm of the cell.
hypertonic solution?
A hypertonic solution has a higher concentration of solutes that the cytoplasm of the cell.
active transport?
Movement of particles across the cell membrane, against the concentration gradient, requires energy and is called active transport.
endocytosis?
Endocytosis is the process by which a cell surrounds an object in the outside environment in a portion of the plasma membrane.
exocytosis?
Exocytosis (think “exit”) is the excretion of materials at the plasma membrane.
cytoplasm?
The environment enclosed by the plasma membrane is a semifluid material called cytoplasm.
cytoskeleton?
The cytoskeleton is a supporting network of long, thin protein fibers that form a framework for the cell and proved an anchor for the organelles.
Microtubules?
Microtubules are long, hollow protein cylinders that form a rigid skeleton for the cell and assist in moving substances within the cell.
Microfilaments?
Microfilaments are thin protein threads that help give the cell shape and enable the part or the entire cell move.
Ribosomes?
Ribosomes are organelles that manufacture proteins.
endoplasmic reticulum (ER)?
The endoplasmic reticulum (ER) is a membrane system of folded sacs and interconnected channels that serves as the site for protein and lipid synthesis.
Golgi apparatus?
The Golgi apparatus is a flattened stack of membranes that modifies, sorts, and packages proteins.
vesicles?
Proteins are packaged into sacs called vesicles, which can fuse to the plasma membrane and release the proteins to the environment.
vacuole?
A vacuole is a membrane bound sac used for temporary storage.
Lysosomes?
Lysosomes are vesicles that contain substances that digest excess or worn-out organelles and food particles.
Centrioles?
Centrioles are organelles made of groups of microtubules that function during cell division.
Mitochondria?
Mitochondria convert fuel particles into usable energy.
chloroplasts?
Plant cells and some other eukaryotes contain chloroplasts, which capture light and convert it into chemical energy in a process called photosynthesis.
cell wall?
Plant cells have a cell wall – a thick, rigid, mesh of fibers that surround the outside of the plasma membrane.
Cilia?
Cilia are short, numerous projections that look like hair.
Flagella?
Flagella are longer and less numerous than cilia.
Move with a whip-like motion
cell cycle?
Cells reproduce by a cycle of growing and dividing called the cell cycle.
Interphase?
Interphase: stage during which the cells grows, carries out cellular functions, and replicates its DNA. Think of interphase as the “warm up.”
Mitosis?
Mitosis: the cell’s nucleus and nuclear material divide; has 4 substages.
Cytokinesis?
Cytokinesis: cell’s cytoplasm divides, creating two new cells.
Interphase has three substages?
G1, S, and G2
Chromosomes?
Chromosomes are the structures that contain the genetic material (DNA).
Chromatin?
Chromatin is the relaxed form of DNA in the cell’s nucleus.
Prophase?
Prophase is the first and longest stage of mitosis.
Cell’s chromatin tightens/condenses into chromosomes.
Sister chromatids?
Sister chromatids are structures that contain identical copies of DNA.
metaphase?
The second stage of mitosis is metaphase – the shortest phase.
Sister chromatids are pulled along the spindle apparatus toward the center of the cell.
They line up in the middle of the cell.
anaphase?
During anaphase, the chromatids pull apart.
Telophase?
Telophase is when the chromosomes arrive at the poles and begin to decondense.
