Cell Structure and Function

Essential Knowledge

• 2B3 – Eukaryotic cells maintain internal membranes that partition the cell into specialized regions.• 4A2 – The structure and function of subcellular components, and

their interactions, provide essential cellular processes.• 4B1 – Interactions between molecules affect their structure and

function.• 4B2 – Cooperative interactions within organisms promote efficiency

in the use of energy and matter.

Cell Theory

1. Every living organism consists of one or more cells.2. The cell is the structural and functional unit of all organisms.3. All living cells arise by division of preexisting cells.4. Cells contain heredity material, which they pass to their offspring

during division.

Prokaryotebacteria cellsTypes of cells

Eukaryoteanimal cells

Eukaryoteplant cells

Differences?

• Identify at least 3 differences between prokaryotes and eukaryotes.

Cell Size

• We already decided that a smaller cell is more efficient.• Why are eukaryotic cells successful despite their significantly larger

size?

Why organelles?

• What is an evolutionary advantage to having organelles?

What do cells do?•It depends on the cell, but some important functions are:•They make proteins!!•They convert energy•They divide

Structure and Function?

• We often learn the functions of all the organelles.

• How are they related?

The parts of the cell must work together

• Making proteins: Nucleus, ER, ribosomes, Golgi apparatus, vesicles, cytoskeleton• Converting energy: Cytoplasm, cytoskeleton, mitochondria,

chloroplasts• Dividing: Nucleus, centrioles

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

Who makes the proteins?

nucleus ribosome ER Golgiapparatus vesicles

The Protein Assembly Line

nuclearpores

nuclearpore

nuclear envelopenucleolus

histone protein

chromosome

DNANucleus

•Function?• Structure?

DNA

NucleusmRNA

nuclearmembrane

smallribosomalsubunit

largeribosomalsubunit

cytoplasm

mRNA

nuclear pore

production of mRNA from DNA in nucleus

mRNA travels from nucleus to ribosome in cytoplasm through nuclear pore

1

2

Nucleolus

• Function • ribosome production

• build ribosome subunits from rRNA & proteins• exit through nuclear pores to cytoplasm &

combine to form functional ribosomes

smallsubunit

large subunit

ribosome

rRNA &proteins

nucleolus

smallsubunit

largesubunit

Ribosomes

0.08mm

RibosomesRoughER

SmoothER

Structure function?

membrane proteins

Types of Ribosomes

• Free ribosomes• Bound ribosomes

Endoplasmic Reticulum

• How is the structure of the ER related to its function?

Types of ER

rough smooth

Smooth ER function

•Membrane production•Many metabolic processes• synthesis• synthesize lipids • oils, phospholipids, steroids & sex hormones

• hydrolysis• hydrolyze glycogen into glucose• in liver

• detoxify drugs & poisons• in liver• ex. alcohol & barbiturates

Synthesizing proteins

cytoplasm

cisternalspace

mRNA

ribosome

membrane ofendoplasmic reticulum

polypeptide

signalsequence

ribosome

Golgi Apparatus• Structure and function?

transport vesicles

secretoryvesicles

Golgi Apparatus

Vesicle transport

vesiclebuddingfrom roughER

fusionof vesiclewith Golgiapparatus

migratingtransportvesicle

protein

ribosome

DNA

RNA

ribosomes

endoplasmicreticulum

vesicle

Golgi apparatus

vesicle

proteinon its way!

protein finishedprotein

Making Proteins

TO:

TO:

TO:

TO:

nucleus

proteins

transportvesicle

Golgiapparatus

vesicle

smooth ER

rough ER

nuclear porenucleus

ribosome

cellmembrane protein secreted

cytoplasm

Making proteinsPutting it together…

Cell Membrane

• Structure• Fluid Mosaic Model

• How does this contribute to its function?

Modeling

• Diagram the cell membrane. Label the following parts: lipid bilayer, integral proteins, peripheral proteins, cholesterol, cytoskeleton, extracellular matrix, glycoproteins, glycolipids. Explain the function of each part of the cell membrane in contributing to the functioning of the cell.

Vacuole

Lysosome

Lysosomes maintain a pH of 5.0 and contain 40 different enzymes. Structure/Function?

Mitochondria

Chloroplast

Cell Wall

How does the structure of the cytoskeleton contribute to its function?

Cytoplasm

Centrioles

Cilia & Flagella

Not all cells are built the same way…

• The structure of a cell dictates the function!

Why?!?!?

• Muscle cells are packed with mitochondria and protein fibers (actin & myosin)• Fat cells contain globular structures filled with fatty acids• Leaf cells are packed with chloroplasts• Potato cells are packed with large vacuoles