UNIT 3Systems

(1.1) Cell Parts

(p3-15)

WHAT YOU WILL LEARN:

• Special structures of cells which perform important life functions.

• Technologies used to study cells.

• Similarities and differences between plant and animal cells.

Why Study Cells?• Studying cells helps us

understand how organisms, like humans, function.

• Think about it.... Do you think the cells in the grass are the same as the cells in the elephants? Are all grass cells the same?

Copyright © 2010 McGraw-Hill Ryerson Ltd.

Big IdeasBig Ideas

The following terms describe different levels of organization in many-celled living things.

Place the four terms in order, from the smallest level of organization to the largest level of organization.

organs

tissues

cells

systems

Robert Hooke

• 1635 -1703

• Credited with the discovery of the cell

• Looked at cork cells (plant)

• Thought that the “empty” spaces

were for fluid passage in plants

• He had no idea how important

this discovery was to be.

Technology of cell study

• Earlier scientists used simple light microscopes to observe cells.

• While these microscopes did help learn about the external structures of the cell they revealed few details about the structures inside cells.

• Today electron microscopes allow scientists to see deep into a cell.

The Cell Theory

1: All living organisms are made up of cells.

2: The cell is the basic structural unit of living organisms.

3: The cell is the basic functional unit of living organisms.

4: All cells come from pre-existing cells.

Organelle

An organelle

- is a structure within a cell

- carries out special functions to support

the life of the cell including:• intake of nutrients

• waste removal • release and generation of energy for the cell• reproduction• production of material that the cell needs

Cell Parts & Function

• Each organelle has a specific role within a cell.

• Some cells have more of one type of organelle and fewer of others.

• Cells exist in great variety.

- Animal cells are different than plant cells.

- In animals cells nerve cells, heart cells, skin cells, bone cells are all different.

• However, cells consist of basically the same structures or parts.

Copyright © 2010 McGraw-Hill Ryerson Ltd.

Animal Cell Organelles (p14)Animal Cell Organelles (p14)

Copyright © 2010 McGraw-Hill Ryerson Ltd.

Plant Cell Organelles (p15)Plant Cell Organelles (p15)

Cell Membrane

• Every cell has a cell membrane

• Forms a protective barrier around the cell

• Designed to allow different substances to move in and or out of the cell.

Cytoplasm

• Organic fluid in all cells

• Composition varies

• Contains material needed by cell to

perform cell functions

Mitochondria• (singular-mitochondrion)

• Tiny, sausage-shaped structures

• Release energy for cell functions

• Called the "powerhouse“

of cell

Ribosomes

• Small, dense-looking organelles that may be attached to rough endoplasmic reticulum or free floating in the cytoplasm.

• The site where proteins are assembled.

Endoplasmic Reticulum

• Small interconnected tubes that carry material around the cell.

• Two Types: Rough ER and Smooth ER

• Rough ER has ribosomes attached.

Vacuoles and Vesicles

Vacuoles and Vesicles - clear, fluid-filled sacs- used for storage of water, food, minerals,

and wasteVacuoles - larger and less numerous in plant cells - smaller in animal cellsVesicles - transport substances throughout the cell

Plant & Animal Vacuoles

Golgi Body

• (Also called Golgi Apparatus)

• Take proteins from the endoplasmic reticulum and modify, sort, and package them for delivery throughout the cell.

Nucleus

• A large organelle usually found near the

center of the cell

• Control center of the cell, directs all cell

activity

• Involved in cell division, contains

chromosomes containing DNA

organized into units called genes

Cytoskeleton

• Filaments and tubules within cell

• Provide framework for cell

• Helps cell keep its structure

• Aids movement of materials in and out of cell

Cell Wall

• Only in plant cells

• Tough rigid structure outside of cell membrane

• Provides support for cell

Chloroplasts

• Found only in plant cells

• Contain a green pigment called chlorophyll used in photosynthesis

• Through photosynthesis energy from the Sun is trapped and glucose is formed

Plant & Animal Cell Comparison

Plant Cells Animal Cells

• Chloroplasts•Large central vacuole• Fixed shape

(rectangular)

• No chloroplasts• Small, numerous

vacuoles• Irregular shape

Tools for Cell Research

• Cells are VERY small.

• Today biologists use different microscopes to explore cell structure and function.

compound light microscope

electron microscope

Animal Cells - Examples

blood cells nerve cells

cheek cells

Plant Cells-Examples

onion cellselodea plant cells

HOMEWORK

• Textbook:

p 13 LC #1-4

p 15 LC #1-3