Cell Structure & Function

Cell Structure & Function

Cell Basics

• Cells are the basic unit of structure and function in all living things

• all living things are made up of cells

Cell Theory

3 Parts of the Cell Theory:

• All living things are made up of cells

• Cells come from preexisting cells

• Cells are the basic unit of structure and organization in living things

2 types of cells:

Prokaryotic - unicellular

Eukaryotic - multicellular

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Types of Cells

• Does not have membrane-bound organelles

• Does not have a nucleus

• Ring-shaped DNA

• Simple organisms

  • Ex: Bacteria

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Prokaryotic Cells

• ​Do contain membrane-bound organelles

• Contains a nucleus

• Linear DNA

• More complex organisms

• Animals, plants, algae, protists, fungi

Eukaryotic Cells

Similarities

Prokaryotic & Eukaryotic Cells

• Contains DNA

• Has a plasma membrane

Multiple Select

What are the three parts of the cell theory? Click all that apply!

• All living things are made up of cells

• Cells are the basic unit of structure and organization

• Cells are the smallest living thing

• Cells come from pre existing cells

Cell Size Limitations

Smaller cells function more efficiently!

• Nutrients and waste must travel in and out of the cell

• The larger the cell, the longer it takes

• Smaller cells = quicker transport

  • more efficient

  • functions better

Cellular Organelles

A strong barrier that provides support and protects plant cells.

Cell Wall

Paired organelles that assist during cell division.

Centrioles

Site of photosynthesis in plants.

Chloroplast

Projections from the cell's surface that help with movement and feeding.

Cilli

​Framework for the cell found in the cytoplasm.

Cytoskeleton

Highly folded membrane where protein production takes place.

Endoplasmic Reticulum

Projection that helps with movement and feeding; usually singular or paired.

Flagella

Modifies and packages proteins to be distributed around the cell.

Golgi Apparatus

Vesicle that contains digestive enzymes that break down old cell material.

Lysosome

Powerhouse of the cell! Creates energy for the rest of the cell to use.

Mitochondria

Control center of the cell. Contains the cell's DNA, which is used for protein production and cell division.

​​Nucleus

Site of protein synthesis. Can be floating in the cytoplasm, or attached to the ER.

Ribosome

Vesicle that stores materials.

Vacuole

A flexible boundary that controls what comes into and out of the cell.

Plasma Membrane

Match

Match the following organelles to their function.

• Nucleus

• Mitochondria

• Endoplasmic Reticulum

• Golgi Apparatus

• Lysosomes

The control center of the cell

The powerhouse of the cell

Folded membrane where proteins are made

Modifies, sorts, and packages proteins

Contains enzymes that break down waste

• The control center of the cell

• The powerhouse of the cell

• Folded membrane where proteins are made

• Modifies, sorts, and packages proteins

• Contains enzymes that break down waste

Match

Match the following organelles to their function

• Vacuole

• Ribosome

• Cell Wall

• Chloroplast

• Cilia

Storage vesicle

Small structure-site protein synthesis

Strong barrier that supports plant cells

Site of photosynthesis

Small projections that help movement

• Storage vesicle

• Small structure-site protein synthesis

• Strong barrier that supports plant cells

• Site of photosynthesis

• Small projections that help movement

The Plasma Membrane

Thin, flexible boundary that controls what enters and exits the cell.

Research where to find the organelles. Plant or Animal cells?

Open Ended

What is homeostasis?

The Plasma Membrane

• Also called the cell membrane

• Thin, flexible boundary between the inside of the cell and the outside environment

  • Lets nutrients and materials in

  • Lets wastes out

Cell ​

​Waste

Nutrients

Ability to allow some substances to pass through, while keeping others out.

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Selective Permeability

Open Ended

Can you come up with an example of something that is selectively permeable?

• Made up of mainly phospholipids, with other molecules

• Phospholipid Bilayer - two layers of phospholipids arranged tail to tail

  • heads = hydrophilic

  • tails = hydrophobic

Structure of Plasma Membrane

• ​Receptor Proteins - found on the outside of the membrane

  • receive signals

  • Peripheral Proteins

• Transport Proteins - create tunnels and channels for substances to move across the membrane

  • Integral Proteins

Proteins

Attach to proteins to receive chemical signals.

​​Carbohydrates

Found between the lipid tails to prevent them from sticking together. Keeps the membrane flexible!

Cholesterol

Fluid Mosaic Model

• Phospholipids create a "sea" that other molecules can float on

  • Lipids move side to side

  • Proteins and carbohydrates move with them

• Mosaic - comes from the different components in the membrane

Cellular Transport

​Carbohydrate

Transport Protein

Receptor Protein

Phospholipid Bilayer

Cholesterol

Cellular Transport

2 Types of Transport

• Passive Transport - does not require energy

  • substances move from high to low concentration

• Active Transport - requires energy

  • substances move from low to high concentration

Transport Basics

• Particles in solids, liquids, and gases are in constant motion

• Concentration - amount of particles in a given space at a given time

• Concentration gradient - unequal distribution of particles

  • high concentration fades to low concentration

Draw

Circle where the concentration is the highest.

Passive Transport

Particles move from areas of high concentration to low concentration

• ​move right through the membrane in cells

• temperature, pH, and pressure influence rate

• Oxygen and carbon dioxide
  

Simple Diffusion

Diffusion will occur until there is equal concentration throughout.

Particles still move, just at equal rates

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Dynamic Equilibrium

Multiple Choice

What does facilitate mean?

• To dissolve

• To make easier

• To connect

• To block

Facilitated Diffusion

• Diffusion where transport proteins help move molecules across the membrane

  • High concentration --> Low concentration

• Large molecules, like glucose, need help to diffuse across the membrane

• Proteins create channels for molecules to use

Draw

Draw an arrow to show which way the particles are going to move.

Osmosis

Osmosis is the movement of water.

• movement of water from areas of high to low concentration

• REMEMBER solutions - solutes are particles, solvent is water

  • Water moves to where the solute concentration is higher (less water)

• High --> Low concentration

• Water will move to an area where there is less water

• This is SO important for our bodies!

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Osmosis

LOW solute concentration
HIGH water concentration

Water moves INTO the cell.
Expands like a hippo!

Hypotonic

​Equal concentration of water and solute.

Water moves in and out equally.
Cell stays the same!

Isotonic

HIGH solute concentration
LOW water concentration

Water moves OUT of the cell.
Cell shrivels like a raisin!

Hypertonic

Active Transport

Active Transport

Transport that requires energy

• Sometimes substances move against the concentration gradient

  • low concentration --> high concentration

• Requires proteins or vesicles

• Requires energy

Pump that maintains the level of sodium and potassium inside and outside of the cell.

Uses energy to pump sodium out and potassium in.

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Na⁺/K⁺ Pump

Surrounds particle and bring it Inside the cell.

Uses portion of the cell membrane to create a vesicle.

​​Endocytosis

Surrounds particle inside the cell and moves it out through the cell membrane.

Vesicle fuses with the membrane.

Exocytosis