Chapter 3 Flashcards
Osmosis
The diffusion of water molecules through a selectively permeable membrane from one region to another.
Plasma Membrane
The outer boundary of a cell that is selectively permeable. phospholipid bilayer, which proteins are suspended.
Nucleus
The dense center of an atom, composed of protons and neutrons. Control center.
Mitosis
four-step process that creates new cells
Adipose cells
Insulate and protect underlying cells and store energy
Shapeless, clumped
Epithelial cells
Protect underlying cells in skin and organs
Flat, tightly packed
Muscle cells
Contract and pull structures closer together
Thin, rod-like
Nerve cells
Transmit nerve impulses from one part of the body to another
Long, threadlike
The cytoplasm
is a fluid that surrounds and moves around the nucleus
Selective permeability
The selective process the body uses to allow or refuse the entry of bodily fluids into and out of cells.
Organelles
In the cytoplasm provide the power, cleaning capability, and building blocks for replicating and maintaining the cell.
Lysosomes
Destroy an transport waste from the cell.
Mitochondria
Release energy from nutrients and convert it into usable energy for the cell’s work.
Ribosomes
Protein particles and RNA that help the cell build proteins.
Endoplasmic reticulum
A double-walled membrane network inside a cytoplasm.
Cell division
The process of a single cell splitting into two daughter cells, each with genetic material that is identical to the original cell.
Interphase
Cell grows and maintains its function; for cells that divide duplicates genetic material
Mitosis
This is the period of cell division in non-sex cells
Cyptoplasmic division
The cell elongates and muscle like filaments pinch the cell in two after mitosis is complete
Telomeres
DNA located at the tips of chromosomes; physically control the number of times a cell will divide.
Prophase
In prophase, chromatin condenses into short dense rods called chromosomes for easier distribution to daughter cells.
Metaphase
In metaphase, chromosomes line up along the center of the cell.
Anaphase
In anaphase, each centromere divides, and chromatids separate from each other.
Telophase
In telophase, chromosomes cluster on each side of the cell.
Chromatin
Nucleic acids and proteins in the cell nucleus that stain readily with basic dyes and condense to form chromosomes during cell division.
Osmotic Pressure
the force required to prevent the movement of water across a selectively permeable membrane. Force that pulls water across the plasma membrane
Light microscope
allow us to visualize the general features of cells.
Electron microscopes
allow us to visualize the fine structure of cells.
Lipids
give the plasma membrane most of its structure and some of its function.
Transport proteins
include channel proteins, carrier proteins, and ATP-powered pumps
Receptor proteins
are linked to and control channel proteins.
Membrane proteins
function as marker molecules, attachment proteins, transport proteins, receptor proteins, and enzymes.
Lipid-soluble molecules
pass through the plasma membrane readily by dissolving in the lipid bilayer.
Large, non-lipid-soluble molecules and ions (e.g., glucose and aminoacids)
are transported through the membrane by transport proteins.
Vesticles
Large, non-lipid-soluble molecules, as well as very large molecules and even whole cells, can be transported across the membrane in vesicles.
Diffusion
is the movement of a substance from an area of higher solute concentration to one of lower solute concentration (down a concentration gradient). uniform distribution of molecules. No energy
The concentration gradient
is the difference in solute concentration between two points divided by the distance separating the points.
The rate of diffusion
increases with an increase in the concentration gradient, an increase in temperature, a decrease in molecular size, and a decrease in viscosity.
Isosmotic solutions and
have the same concentration of solute particles - cells neither sink nor swell
hyperosmotic solutions
have a greater concentration of solute particles - shrink or crenate
hyposmotic solutions
have a lower concentration of solute particles - swell or lysis
Mediated transport
is the movement of a substance across a membrane by means of a transport protein. The substances transported tend to be large, water-soluble molecules.
Facilitated diffusion
moves substances down their concentration gradient and does not require energy (ATP).
