Chapter 7: Cell Structure and Function
cell wall
The outermost layer of cells in plants, bacteria, fungi, and many algae that gives shape to the cell and protects it from infection
chloroplast
The purpose is to make sugars that feed the cell's machinery
Cells are the basic structure and function of a living thing, All organisms (living things) are made out of cells, only existing cells can make new cells
What are the three parts of the cell theory?
Eukaryotic cells contain membrane-bound organelles, including a nucleus. Prokaryotic cells do not contain a nucleus or any other membrane-bound organelle.
What is the difference between prokayotes and eukaryotes?
nucleus
a dense organelle present in most eukaryotic cells, typically a single rounded structure bounded by a double membrane, containing the genetic material.
vacuole
a membrane-bound cavity within a cell, often containing a watery liquid or secretion.
prokaryote
a microscopic single-celled organism that has neither a distinct nucleus with a membrane nor other specialized organelles
ribosome
a minute round cytoplasmic particle composed of RNA and protein that is the site of protein synthesis as directed by mRNA
endoplasmic reticulum
a network of tubular membranes within the cytoplasm of the cell, occurring either with a smooth surface or studded with ribosomes and is involved in the transport of materials
cell theory
a scientific theory which describes the properties of cells. These cells are the basic unit of structure in all organisms and also the basic unit of reproduction
lipid bilayer
a universal component of all cell membranes. Its role is critical because its structural components provide the barrier that marks the boundaries of a cell, it is composed of two layers of fat cells organized in two sheets
mitochondrion
an organelle that performs the process of aerobic respiration. In aerobic respiration, simple food molecules like glucose are broken down for their energy. The process results in high-energy molecules called ATP (powerhouse of the cell)
Golgi apparatus
an organelle, consisting of layers of flattened sacs, that takes up and processes secretory and synthetic products from the endoplasmic reticulum and then either releases the finished products into various parts of the cell cytoplasm or secretes them to the outside of the cell
eukaryote
an organism consisting of a cell or cells in which the genetic material is DNA in the form of chromosomes contained within a distinct nucleus
cytoskeleton
consists mainly of actin filaments and microtubules and plays an important role in cell movement, shape, growth, division, and differentiation, as well as in the movement of organelles within the cell. All eukaryotic cells have one
Chloroplasts capture energy from sunlight and convert it into food that contains chemical energy in a process called photosynthesis. The mitochondria converts the chemical energy stored in food into compounds that are more convenient for the cell to use.
describe the function of the chloroplasts and mitochondria in the cell
Vacuoles store materials like water, salts, proteins, and carbohydrates. Lysosomes break down lipids, carbohydrates, and proteins into small molecules that can be used by the rest of the cell. They are also involved in breaking down organelles that have outlived their usefulness. The cytoskeleton helps the cell maintain its shape and is also involved in movement.
describe the role of vacuoles, lysosomes, and the cytoskeleton.
The cell membrane regulates what enters and leaves the cell and also protects and supports the cell.
describe the structure and function of the cell membrane
the movement of ions or molecules across a cellular membrane from a lower to a higher concentration, requiring the consumption of energy.
describe the term active transport
transport of a substance across a cell membrane by diffusion; expenditure of energy is not required
describe the term passive transport
lysosome
A cell organelle that is surrounded by a membrane, has an acidic interior, and contains hydrolytic enzymes that break down food molecules, especially proteins and other complex molecules
The nuclear envelope surrounds the nucleus and all of its contents. There are pores and spaces for RNA and proteins to pass through while the nuclear envelope keeps all of the chromatin and nucleolus inside. contains the cell's hereditary information and controls the cell's growth and reproduction. It is the command center of a eukaryotic cell and is commonly the most prominent organelle in a cell.
Describe the structure and function of the cell nucleus.
hypotonic
has a lower concentration of solute than the cell causing water to diffuse into the cell. The cell will swell and could burst. solutes are decreased
hypertonic
has higher concentration of solute than the cell, water diffuses out and the cell shrivels. solutes are increased
The Golgi Apparatus modifies, sorts, and packages proteins and other materials from the endoplasmic reticulum for storage in the cell or release outside the cell. Endoplasmic Reticulum (ER) The endoplasmic reticulum is where lipid components of the cell membrane are assembled, along with proteins and other materials that are exported from the cell. Ribosomes are small particles of RNA and protein found throughout the cytoplasm in all cells. Proteins are assembled on ribosomes.
identify the role of ribosomes, endoplasmic reticulum, and golgi apparatus in making proteins.
organelle
little organs that perform various functions
facilitated diffusion
process by which substances are transported across cell membranes by means of protein carrier molecules
centriole
structure in an animal cell that helps to organize cell division
cytoplasm
the jellylike material that makes up much of a cell inside the cell membrane, and, in eukaryotic cells, surrounds the nucleus.
osmosis
the movement of water molecules through a selectively permeable membrane from higher water concentration to a lower water concentration
diffusion
the net passive movement of particles (atoms, ions or molecules) from a region in which they are in higher concentration to regions of lower concentration. It continues until the concentration of substances is uniform throughout.
isotonic
the same concentration of solute as the cell so water diffuses in and out evenly
cell membrane
the semipermeable membrane surrounding the cytoplasm of a cell.
cell
the smallest structural and functional unit of an organism
