Cells Unit 3 chapter 7
- Basic unit of structure and function of living things.
- Tiny organs within cells.
All living things are made up of cells.
Cells are the basic units of structure and function in living things.
Living cells come only from other living cells.
Hooke - Observe room-like structures he
called “cells” 1665.
Van Leenwenhoek - Made simple microscope-saw
scientists whose work led to cell theory.
Schleiden - Botanist
Schwann - Botanist
Virchow - Physician
to cell theory - Chloroplasts and
Mitochondria have their own DNA
Virus cannot reproduce
on their own but must invade a living cell. Considered my some scientists to be
Types of cells
Prokaryotes – Smaller and simpler cells – Have membrane and cytoplasm
but no nucleus. Example Bacteria, Kingdom moneran.
Eukaryotes – Larger more complex – Have nuclei and many other
Nucleic acids - Large complex molecules, found in nucleus, store the
information that helps a cell make the substances it needs.
types of Nucleic Acids
1. DNA - Deoxyribonucleic acid.
Stores information needed to build proteins.
2. RNA - Ribonucleic acid.
“Reads” the DNA messages and guides the protein-making process.
- threads of DNA in nucleus, called Chromosomes when Wound up. Carry Traits.
– Where ribosome’s are made.
- Separates the nucleus from the rest of the cell. Has holes in it called pores
which allow RNA and material to move in and out.
Thin, flexible, envelope that surrounds the cell - controls movement of material
into and out of the cell.
wall - only
in plant cells, made of cellulose. Give
– large structure contains cells genetic material (RNA DNA) controls cells
– Material inside the cell membrane but outside the nucleus.
– a network of protein filaments that help the cell maintain shape and
sometimes move. Made of Microtubules and microfilaments
- small made
of RNA produce proteins based on instructions from the nucleus
Endoplasmic Reticulum – maze like passageway – newly made proteins may be modified here cell membranes assembled here
ER has many ribosomes attached to it.
– Stack of membranes like folded garbage bags – here enzymes attach
carbohydrates and lipids to proteins which then move to their final destination
- Small round packets of digestive enzymes.
- large round sacs. (Storage tanks)
Plant cells generally have one large vacuole which stores water.
- Only in plant cells. Contain chlorophyll use energy of the sun to form glucose
(high energy compound) in photosynthesis.
- (rod-shaped) - Supply energy (the powerhouse of the cell).
Break down glucose and store energy in complex molecule. ATP
Chloroplasts and Mitochondria have their own DNA
– Take part in cell division
are like factories labor is divided among parts each with a special purpose.
a cell or within an organism, the work of life processes is divided among
different parts. This is called Division
basic levels of organization from simplest to most complex are:
- Organ Systems
- Cells - Basic unit of structure and
function in all living things, from one-celled organisms to us.
- Tissues - Cells that are similar in
structure and function, joined or working together.
muscle tissue Bone
- Organs - Groups of different
tissues working together.
- Organ Systems - A Group of Organs that work together to perform a certain function.
muscular system skeletal
- Organisms - An entire living thing that carries out all the basic functions of
human, bacterium, pine tree.