Cells Chapter 7

What is a Cell? The basic unit of all forms of life Smallest unit of life

How were cells discovered? Van Leeuwenhoek: 1600’s, invented the microscope Hooke: 1665, first to see cells and names them cells because they remind him of small rooms Schleiden: 1838, all plants made of cells Schwann: 1839, all animals made up of cells Virchow: 1855, all cells come from preexisting cells

The Cell Theory All living things are composed of cells. Cells are the basic units of structure and function in living things New cells are produced from existing cells

Cell Structure Many shapes and sizes 5 – 50 micrometers in diameter Smallest cells = bacteria Large cells = giant amoeba (1000 micrometers)

Basic Cell Structures Cell Membrane = thin, flexible barrier around the cell. Help support and protect the cell and determines what gets in and out of the cell Cell Wall = strong layer outside of the cell membrane (plant cells). Used for support and protection.

Basic Cell Structures Nucleus: controls the cell and holds the genetic material Cytoplasm: material inside the cell membrane (gooey) that holds the nucleus and other cell structures

2 Types of Cells Prokaryotes: no nucleus, small simple, still considered living - Ex. bacteria 2. Eukaryotes: have a nucleus and organelles (cell organs), can live on their own or make up multicellular organisms (plants, animals)

Cell Structures Chapter 7-2

Animal Cell

The Nucleus Controls all of the cell processes Holds the hereditary info (DNA)

Parts of the Nucleus: Chromatin: DNA attached to protein Chromosomes: condensed chromatin, how DNA is passed on to offspring Nucleolus: dense center of nucleus, makes ribosomes Nuclear Envelope: membrane around the nucleus

The Cytoskeleton protein filaments that support and move the cell Microtubules: hollow tubes that move organelles Cilia and Flagella: outside of the cell, move the cell Microfilaments: thin fibers that support the cell

Ribosomes Make proteins Turns RNA into protein using instructions from the nucleus Free = floating in the cytoplasm Attached = attached to the membranes of organelles

Endoplasmic Reticulum (ER) Assembles components of the cell membrane, modifies proteins Rough ER = has ribosomes attached, protein modifier Smooth ER = no attached ribosomes, enzyme collector

Golgi Apparatus Stacks of membranes Packages and sends proteins Attaches carbohydrates and lipids to proteins and then sends them to the rest of the cell to be used

Lysosomes Small organelle filled with enzymes Uses its enzymes to break down lipids, carbohydrates, and proteins so they can be used

Mitochondria Releases energy from food Uses energy from food to make high-energy compounds that the cell can use to power growth, development, and movement

Animal Cell

Plant Cell

Cell Wall Lies outside the cell membrane Lets water, oxygen, carbon dioxide, and other substances pass Provides support and protection for the cell Made up of carbohydrates and proteins (cellulose)

Vacuoles Storage containers Store water, salts, proteins, and carbohydrates Stores liquid and creates pressure that holds the plant up with its flowers and leaves

Chloroplasts Contain the pigment chlorophyll (green) Catches the energy from the sun to make energy-rich food molecules (photosynthesis)

Plant vs. Animal Cells

Cell Summary

Cells gotta work to live! What jobs do cells have to do? make proteins proteins control every cell function make energy for daily life for growth make more cells growth repair Renewal Cells Use Different Organelles to Accomplish the Jobs

Proteins do all the work! cells DNA Repeat after me… Proteins do all the work! organism

Cells functions Building proteins read DNA instructions build proteins Nucleus build proteins Ribosomes process proteins Rough ER, Smooth ER address & transport proteins Golgi Body

Building Proteins Organelles involved nucleus ribosomes endoplasmic reticulum (ER) Golgi apparatus vesicles The Protein Assembly Line Golgi apparatus nucleus ribosome ER vesicles

Any Questions!! 2007-2008