Cells & Cell Structures

9th Grade Science2012

Cell Structures

Animal Cell Plant Cell

Your Cell Organizer

• Each structure has it’s own picture and definition

• We’ll color or outline each structure in the main animal or plant cell picture, and it’s own “highlight” picture, using the same color in both places.

• We’ll fill in the name and function of each organelle in the boxes provided.

• Refer to pgs 112-113 in your book.

Nucleus

• Function: the “brain” or “library”• Manages cell

functions• Contains the cell’s

genetic information • Features:

• Nucleolus and chromatin found inside

Nucleus• Features cont’d:

• Nuclear membrane surrounds the outside• the “baggy” that

holds the nucleus separate from the rest of the cell, contains pores for transport of material in and out

• Makes a cell a eukaryote

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Nucleolus

• Function:• Makes ribosomes

• Features:• Part of the

nucleus

Cytoplasm• the fluid of the cell• Function:

• Supports organelles (like pieces of fruit in jelly)

• Allows chemical reactions

• Features: • Jelly-like• 70-90% water

Plasma Membrane (Cell Membrane)• Function: “Baggie”

that holds the cell together.• Barrier to the outside

environment.

• Feature 1: found around outside of cell

• Feature 2: Selectively permeable: only allows certain substances in and out of cell.

Mitochondria• Function: the center

of cell respiration• Converts glucose

(sugar) from food to useable form of energy called ATP. ATP is used by cells to do work.

• Feature: double membranes, own DNA.

• Both plants and animals have mitochondria

Rough Endoplasmic Reticulum (RER)• Function: Specializes

in making proteins and transporting them

• Feature:• Long membrane

“channels”• Attached to nuclear

membrane.• Does have

ribosomes attached

Ribosomes• Function: make proteins for the cell to use• Feature: Found in two places

• Floating free in the cytoplasm• Attached to the endoplasmic reticulum

Smooth Endoplasmic Reticulum (SER)

• Function: transport and communication, Synthesis of fats (lipids) & carbohydrates

• Features: No ribosomes attached, has tubes and canals.

Golgi Apparatus (Complex, Bodies)

• Function: Makes membranes, creates some products for secretion, packages proteins for storage and/or shipment

• Feature: Looks like stacks of pancakes• Many layers of

membranes

Lysosome• Function: Used to break

down worn out parts of the cell, destroy bacteria, digest foreign particles, remove toxic wastes.

• Feature: Baggies of enzymes• About 40 types

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Vesicles

• Function: Carry finished products to interior or exterior of cell.

• Feature: membranes formed from Golgi,

• “Freight trucks”

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Centrioles• Function:

manufacture proteins for the cytoskeleton

• Features: rings of tubes; a pair at 90° before cell division.

Vacuoles (Both)• Function: Stores

organic materials made by plant, sugars, water or wastes; in animal cells, if present, stores excess water.

• Feature: large fluid-filled sac (“storage baggie,” in plant cells; very small and only a few in animal cells

Cell Wall (Plants only!)

• Function: • Provides rigid

support and structure to plant cells

• Features:• Found outside the

cell membrane.• Made mostly of

carbohydrate

Chloroplast (Plants only!)• Function: convert

light energy into food (sugars and starches)

• Features:• contain pigments

(like chlorophyll) that help capture light energy

• Own DNA• Plastids: Baggies

used to store the pigments

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Cytoskeleton

• Function: provide structure & support to cell; framework for movement within cells.

• Features: lattice/matrix of protein filaments and “motor proteins.”

Organelles

Animal Cell Plant Cell

A Venn Diagram

• A way to find similarities and differences

• We’re going to compare the cells of prokaryotes, plants and animals

• Use list of cell structures & organelles from notes and organizer

• Putting each one into the “zones” they belong in

• If in more than one, put into the shared overlapping zone

Cell Specialization

• In complex organisms, cells go from generic to specialized

• After fertilization cells are called stem cells• Start out out with no specific job to do• Will change over many divisions into cells

with a specific job and location• Stem cells have the potential to become

any specific cell.

Specialization Process

• All new cells (except red blood cells) contain a complete copy of the genetic code

• As the organism develops genes are turned on and off in a specific order

• The sequence tells the cell to mature into a certain type of cell

• The process is called specialization or differentiation

Using Stem Cells

• Much excitement about using them to help cure disease• Replace pancreas cells for people with

diabetes• Replace bone marrow cells for people

with leukemia• Re-grow nerve cells for people who are

paralyzed• Re-grow whole body parts for transplant?

Organelles, cont.

• Some organelles are involved in transforming energy from one form to another (chemical, mechanical, etc).

• Some convert sunlight to food• Others break down food into energy

useable for work in the cell.

Organelles, cont.

• Some organelles are part of a system of protein synthesis (to put together)

• Assembly• Transport• Storage