chapter 7 cell structure and function juan herrera biology period 2

Chapter 7 Cell Structure and Function

Juan Herrera Biology Period 2

The Discovery of the Cell What is the cell theory? We will not be able to see cells with out the microscope All living things are made up of cells Cells are the basic units of structure and function in living things New cells are produced from existing cells.

7.1 Life is CellularSC.912.L.14.1

Microscope

Plant Cell

Early Microscopes The first proto-microscope was used in

1665 Cell are not chambers they actually have a

huge array of working parts. Anton van Leeuwenhoek discovered that

cells are everywhere. Leeuwenhoek was the first to

discover the bacteria in the human mouth.


Anton Van Leeuwenhoek

The Cell Theory Cells are the basic unit of life. Cells can only be formed from pre-existing

cells. Cell theory: All living things are made

up of cells Cells are the basic units of structure

and function in living things New cells are produced from

existing cells.


Exploring the cell How do microscopes work? Microscopes produce an

enlarged image of something very small.

Most microscopes use lenses to magnify the image of an object by focusing light or electrons.


Exploring the cell? Microscopes are still

used to day to explore the cell

Scientist today use really powerfully microscopes.


Light Microscopes and Cell Stains The most common type of

microscope is the compound light microscope.

The objects get magnifying it 1000 times

Dyes are used to solve the transparency problem with most living cells.


Electron Microscopes It is used in to see cells and cell

structures as small as 1 millionth of a meter.

Electron microscopes can be used to get a higher resolution than other microscopes.

2 types of electron microscopes transmission and scanning.

Electron can easily be moved by the air, which mean samples much be placed in a vacuum.


Prokaryotes and Eukaryotes Cell membrane: Semipermeable

barrier that is flexible and protects the cell.

Nucleus: is a large membrane enclosed structure that contains genetic material in the form of DNA.

Eukaryotes are cells that enclose their DNA in nuclei

Prokaryotes are Cells that do not enclose DNA in nuclei.


Cell Organization What is the role of the cell nucleus? Cytoplasm is a portion of the cell outside the

nucleus. Organelles structures that act like specialized

organs. Nucleus contains nearly the cell’s DNA the

coded instruction for proteins and other important molecules.

7.2 Cell StructureSC.912.L.14.3

Comparing the cell to a factory? The cell is like a living factory The different organelles are compared to

specialized machines.


Nucleus Nucleus contains nearly the

cell’s DNA the coded instruction for proteins and other important molecules.

Nucleus has 4 main parts: Nuclear pores, Chromatin, Nucleolus, Nuclear envelope.

Chromosomes carry the cell genetic information

The brain of the cell


Organelles that Store, Clean up, and Support What are the functions of vacuoles,

lysosomes and the cytoskeleton? Vacuoles store, Lysosomes Clean up, and

Cytoskeleton support. These organelles are the storage space,

Clean up crew, and support structures.


Vacuoles and Vesicles? Vacuoles store materials

like water, salts, proteins and carbohydrates.

Many plants have a central vacuole.

If Vacuoles did not exist then the cell would not be able to store materials that it needs to survive.


Lysosome


Lysosomes Lysosomes are small organelles filled with

enzymes. Lysosomes break down lipids, carbohydrates,

and proteins into small molecules that can be used by the rest of the cell. They are also involved in breaking down organelles that have outlived their usefulness.

A lot of human diseases are formed by function failed in the lysosomes.


The Cytoskeleton Shapes the cell’s internal organization by a

network of protein filaments. It involves in movement. There are 2 principle protein filaments

Microfilaments and microtubules.


The Cytoskeleton Microfilaments- Mostly made up of actin,

Microfilaments help the cell move. Microtubules mostly made up of tubulins.

Microtubules help the cell maintain its shape, and are also important in cell division (only in animals)


Organelles that build proteins What organelles help make

and transport proteins? Ribosomes synthesized

proteins Golgi apparatus transports

the proteins and other materials.

Endoplasmic Reticulum assembles proteins and lipids.


Ribosomes Ribosomes are small particle of RNA and

protein found throughout the cytoplasm in all cells.

Ribosomes produced proteins by following coded instructions from the DNA.


Endoplasmic Reticulum ER is where lipids

components of a cell are assembled along with proteins.

Proteins made on the rough ER will be the ones that are released, or secreted from the cell.

Two types of ER- Rough and Smooth.


Golgi Apparatus Golgi Apparatus modifies,

sorts, and packages proteins and other material from the endoplasmic reticulum for storage in the cell or release outside the cell.

The post office of the cell


Organelles that capture and release energy

What are the functions of chloroplast and mitochondria?

Chloroplast- Organelle that captures energy

Mitochondria- Organelle that releases energy


Chloroplast Chloroplast capture the energy from

sunlight and convert it into food that contain chemical energy in a process called photosynthesis.

Chloroplast contains chlorophyll.


Mitochondria (All cells have mitochondria) Mitochondria are the power of the cell.

(Powerhouse) Mitochondria convert the chemical energy

stored in food into compounds that are more convenient for the cell to use.

Both Mitochondria and Ceroplastic contain their own genetic material. ( Supporting the endosymbiotic theory)


Cellular boundaries What is the function of

the cell membrane? All cells have a cell

membrane it protects the cell, and keeps its products safe.

Plants have an additional cell boundaries the cell wall.


Cell wall Main functions is to give

support, shape, and protect the cell.

Cells wall are porous (allowing material in) which allows water, oxygen, and other certain substances to access the cell.


Cell Membrane All cells have a cell

membrane, which is made by a lipid bilayer which give the cell the flexibility that it needs.

The Cell Membrane is semi-permeable which means it allows some materials into the cell.


Passive transport What is passive transport? Passive transport if transport that does not

require energy. It keeps the water levels in the cell constant.

7.3 Cell Transport Sc.912.L.14.2

Diffusion Diffusion: Process by which particles move

from an area of high concentration to an area of lower concentration.

Diffusion depends on random particle movements.


Facilitated Diffusion Facilitated diffusion- Molecules that cannot

diffuse across the membrane pass through special proteins which is called Facilitated diffusion.

Protein act like carriers making them easier to let some molecules go through.


Osmosis Aquaporin- Are water

protein channels hat allow water to pass through them.

Osmosis: Diffusion of water through some semi-permeable membranes.


Osmosis Some membranes are just permeable to

water and nothing else. Water will keep diffusion until equilibrium is

reached. After equilibrium is reached then both

solution on each side of the membrane become isotonic.

When both solution are not isotonic then one in hypertonic and the other hypotonic.


Osmosis pressure Osmotic pressure is the force by which a

substance exerts on a semipermeable membrane.

Is causes a hypertonic solution to shrink, and a hypotonic solution to swell.


Active Transport What is active transport? Active transport is the

movement of materials against a concentration different. It requires energy.

Sometime active transport can change the shape of cells.


Molecular transport Small molecules act like pumps in active

transport. A large amount of energy is used to keep up

active transport.


Bulk Transport Large molecules and solid clumps can be

transported by Bulk Transport. Endocytosis is the process of taking

materials into the cell by means of in folding. Exocytosis- Release of large amounts of

materials.


endocytosis and exocytosis


The cells as an organism How do individual cells maintain

Homeostasis? Homeostasis: To maintain constant internal

physical and chemical conditions. To maintain homeostasis, unicellular

organism grow in response to the environment, transform energy and reproduce.

7.4 Homeostasis and CellsSC.912.L.14.2

Multicellular life How to cell of multicellular organism

maintain homeostasis? The cells of multicellular organism become

specialized for particular task communicate with one another.

Multicellular organism cells don’t live on their own.


Cell specialization Many cells are specialized for one purpose

(Movement, reacting to the environment, Substances that the organism needs).

ALL SPECIALIZED CELLS CONTRIBUTE TO HOMOESTASIS!!!!!!!!


Levels of organization Cells<Tissue<Organ<

Organ System Tissue- Group of

similar cells Organ-Group of similar

tissues Organ System- Group

of similar organs


Cellular communication Chemical signals are used to communicate

from one cell to another. The receptor is the molecule that receive a

signal.


chapter 7 cell structure and function juan herrera biology period 2

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