Cells and Body Systems
"Cell Power"
Humans are complex, multi-cellular organisms, but this song about them is easy to understand. The song reviews all the parts of the cells and the roles that they play. We travel inside the nucleus and then explain how larger body systems work. And we break the facts down like carbohydrates break into ATP.
Intro
Hey now children, settle down.
Today we’re going to talk about
life. There are six ways to know
you’re alive for sure.
1. Living things have cells
2. They use stimuli to maintain a
homeostasis.
3. They have DNA.
4. They reproduce.
I said no laughing!
5. They live, thrive, and die.
6. They use energy.
Ayo, first things first:
There’s three different types of
Living things on the Earth.
Ya heard?
There’s organisms with one cell,
Whose life functions are
Performed by organelles.
And green plants use
Photosynthesis,
A chloroplast converts sunlight
And lives with it.
And last are the animals, listen,
Cells, tissue, organ-to-organ system.
And they’re unique;
I can’t lie, homes,
Only animal cells
Contain lysosomes.
But all cells contain ribosomes.
They make proteins,
The building blocks, I suppose.
But don’t get caught slipping
On the oils and the fats,
A.k.a. the lipids.
Cells need fuel — they break
Carbohydrates Into ATP,
Adenosine triphosphate.
Alright y’all! Cell theory has three
parts:
1. All living things are composed of
one or more cells.
2. The cell is the basic unit of life in
all organisms.
3. All cells come from existing cells.
On top of that, they all have a
cell membrane surrounding the
cytoplasm, and most plants and
bacterium have a cell wall.
Now let’s travel
To the center of the cell,
The nucleus,
Where nucleic acids are held.
They form DNA, the genetic code,
And multiply by mitosis
If you let it go.
It’s incredible, like the duty is
Of mitochondria —
Extract energy from nutrients.
And did I mention,
The spot they make the lipids in,
Is the ER, or
Endoplasmic reticulum?
And the Golgi complex is next to it,
Delivering the products of the ER
— excellent!
To hit the exit,
You could use diffusion,
The membrane will pass
In or out of solution.
Of all movement,
The cell has control,
To dispose of waste in a vacuole.
And that can use active transport,
To either squeeze out or ingest
Something, so plan for it.
Okay y’all, you know us humans
are a complex, multicellular
organism. We have many systems
made of specialized cells, tissues,
and organs. You know, systems
like the digestive, respiratory,
cardiovascular, excretory,
reproductive, and nervous systems
— and all of these systems work
together, to keep homeostasis of
man. Cell power!
Oh, to be human,
Word to my circulatory
That stays moving.
I got heart, got blood, got arteries,
Veins drain back to my heart.
And plus, guarding me
Are antibodies,
Part of my immune system,
Peace to my muscles and bones;
I move with them.
It’s in coordination
With the brain and the spine,
My central nervous design.
When neurons are sent
Through my peripheral,
And the endocrine is closely
Connected with it, yo,
Secreting hormones,
Chemical messengers.
And respiration works
Every time a breath occurs.
Oxygen will release the energy
Of food that we digest,
So let me eat!
And if I gotta excrete,
Sweating through my skin,
That’s ’cause I got heat!
Alright y’all! Now who in here can
spell flagella? And who knows
where the word came from, "cell"?
Anybody know that it’s Latin?
Cellula means "small room." Now
before y’all go, let me remind you:
Don’t forget to respect the building
block of life. Give it up for cells,
y‘all! Alright, class dismissed. Class
dismissed. Get your flagella out of
here.
Flocab Spits Facts:
Use Your Muscles
Life in the Solar System
Virus
Take Your Pulse
Can a robot ever be alive? What about a computer? What about you - are you alive? How can you tell if something is alive or not? There are six ways you can check to see if your computer, your favorite robot, or you are, in fact, "alive." The first important test is to see if they have cells.
Cells are the basic structure of all living organisms. They were first discovered in 1665 when a British scientist named Robert Hooke looked at a slice of cork under a microscope. He was amazed to see that this soft tree bark was actually made of thousands of tiny boxes or rooms, which he called cells. Then, in 1673, another scientist named Anton van Leeuwenhoek (LAY-vauh-hook) built a handmade microscope and looked at a drop of pond water. To his amazement, he saw thousands of tiny creatures he called animacules, or little animals, swimming around. He later examined human blood, the yeast cells that make bread rise, and bacteria.
This Robot Has Conducted an Orchestra
Cells are the basic structure of all living organisms. They were first discovered in 1665 when a British scientist named Robert Hooke looked at a slice of cork under a microscope. He was amazed to see that this soft tree bark was actually made of thousands of tiny boxes or rooms, which he called cells. Then, in 1673, another scientist named Anton van Leeuwenhoek (LAY-vauh-hook) built a handmade microscope and looked at a drop of pond water. To his amazement, he saw thousands of tiny creatures he called animacules, or little animals, swimming around. He later examined human blood, the yeast cells that make bread rise, and bacteria.
This Robot Has Conducted an Orchestra
All living things have cells. A cell is a structure, usually microscopic in size, covered by a membrane that contains all the materials needed for life. Some organisms have just one cell while others are built of trillions of specialized cells, each performing a different special function.
Living things sense changes in their environment called stimuli, such as chemicals, sounds, touch, light, gravity, and darkness. Organisms respond to a stimulus so they can maintain a stable environment inside the cell, a stability called homeostasis. Homeostasis is necessary for the different chemical reactions that take place within the cell.
Living things have DNA, or deoxyribonucleic acid. DNA contains directions for the cell to produce proteins that help determine the organism's characteristics and structures.
Living things reproduce, either asexually (which produces offspring identical to the parent) or sexually (which combines traits from a male and a female parent). These traits are passed on through duplication of a cell's DNA.
Living things grow, thrive, and eventually die. Some organisms change their form as they grow because their DNA codes for the formation of different proteins.
Living things use energy for activities like making food, breaking down food, moving materials in and out of the cell, locomotion, and reproduction. Because they are able to do all this, it means that they can breathe, eliminate waste materials, and either use nutrients or can create nutrients using another source of energy, such as sunlight.
While there are six kingdoms of living things, three categories are sufficient to compare the functions of different organisms: one-celled organisms, plants, and animals. All demonstrate the six characteristics of living things.
One-celled organisms have all the materials they need to survive inside one tiny cell. Tiny specialized structures called organelles help the cell complete all the functions of life.
Green plants have several specialized structures, or groups of cells, to carry out the six functions of living things - structures like roots, stems, leaves, flowers, and seeds. Plants require air, water, nutrients, and light. Using sunlight, they take in carbon dioxide, create carbohydrates or sugars they can store as food, and give off oxygen and water.
Green plants may have another structure in their cytoplasm called a chloroplast. During photosynthesis, a chloroplast is responsible for using light energy from the sun to produce carbohydrates, which can be used or stored as food.
Multicellular animals, such as humans and dogs, need oxygen, water, and food to live. These organisms have specialized cells that are grouped into tissues and organs, creating specialized organ systems for carrying out major life activities. While animals differ greatly in their size, shape, and complexity, they share similar systems for carrying out the six functions of life.
Lysosomes are found only in animal cells. These small structures contain enzymes that are used to break down ingested materials or damaged organelles so they can be replaced. Sometimes they are used to dissolve cells no longer needed by an organism. For example, lysosomes dissolve the tail cells of a tadpole as it becomes a frog and develops legs, and the body cells of a caterpillar while it grows wings to become a moth.
Cells function similarly in all living things. They grow and divide to produce more cells; they take in nutrients to provide energy and make the materials that a cell or organism needs; and they're made of molecules that generally contain different combinations of six elements: carbon, hydrogen, nitrogen, oxygen, phosphorous, and sulfur. These elements combine to form proteins, carbohydrates, lipids, nucleic acids, and ATP. Throughout the cell, ribosomes
are what build proteins from simple molecules called amino acids.
are what build proteins from simple molecules called amino acids.
Proteins are the building blocks of cells, created by linking amino acids. The DNA of a cell includes coding for building these different proteins based on the genetic coding and function of the cell.
Nucleic acids are made of nucleotides, complex molecules that help the cell form proteins. DNA, which regulates cell development, reproduction, and protein formation, is a nucleic acid. In most cells this material is located in the nucleus of the cell, although more primitive organisms, like bacteria, don't have a separate nucleus.
Lipids are fats and oils that help form cell membranes and store energy for a cell to use. Whereas plants generally store unused energy as carbohydrates, animals usually store it as lipids in specialized fat cells.
Carbohydrates are combinations of carbon, water, and oxygen. Cells use carbohydrates as a source of energy. When we eat plant materials like lettuce, rice, wheat, or potatoes, we take the carbohydrates stored in the plants' cells and convert them to sugars that our cells can use for energy.
ATP or adenosine triphosphate is the major fuel for cells. By breaking down carbohydrates or fats, energy is released that is transferred to ATP molecules for use by cells.
Two hundred years after Hooke and Leeuwenhoek discovered cells, a group of German scientists developed what we now call the cell theory. It has three parts: All living organisms are composed of one or more cells. The cell is the basic unit of life in all living organisms. All cells come from existing cells.
All cells share certain characteristics and have certain structures. Each has a cell membrane that surrounds the cytoplasm, or material inside the cell. In most plants and bacterium, this membrane is covered by a cell wall that keeps the cell rigid. It was the hardened remains of these cell walls that Hooke first noticed in 1665.
In most animals and single-celled organisms, the cell membrane is less rigid than it is in plants. Many single-celled organisms have locomotion organelles that help them to move. These might include a whiplike tail called a flagellum, tiny hairlike structures called cilia that can push the organism along by waving, or the ability to push a part of the cell forward to form a structure called a pseudopod, so its cytoplasm can flow and drag the rest of the cell into a new position.
Except for bacteria, most cells have a nucleus in which genetic material like DNA is surrounded by a membrane. For a cell to multiply or split into new cells, DNA molecules must reproduce themselves in a process called mitosis.
Mitochondria extract energy from nutrients. Called the powerhouses of cells, these organelles are where the chemical ATP does its work.
Lipids and other materials used inside the cell and as part of the cell membrane
are produced in the endoplasmic reticulum or ER, which looks like a membrane-covered set of tunnels or flattened tubes. These also help to break down chemicals that might be harmful to the cell.
are produced in the endoplasmic reticulum or ER, which looks like a membrane-covered set of tunnels or flattened tubes. These also help to break down chemicals that might be harmful to the cell.
The Golgi complex is located near the ER. It surrounds and delivers products from the ER to other places in the cell or out of the cell, so they can be used by other structures of a multicellular organism.
The cell membrane performs several important functions in addition to separating the cytoplasm from its outside environment. It controls which molecules enter and leave the cell. One way this is done is through a process called diffusion, in which differing concentrations of a solution can pass either in or out of the cell membrane. For example, if the fluid inside a cell has a higher concentration of carbon dioxide than surrounding fluids, the excess can diffuse outward.
The cell membrane allows for the transfer of organic or inorganic substances in or out of the cell. These substances are dissolved in the cell's cytoplasm so that necessary chemical reactions can take place. Some chemical reactions occur to break down large organic food molecules, such as proteins, into simpler amino acids that the cell can use to rebuild, repair, and reproduce itself. Other chemicals help break down complex carbohydrates like starches into simple sugars that can enter the cell and be used as nutrients to provide energy.
Most cells have a specific set of organelles inside its cytoplasm to carry out its main functions. Each organelle must coordinate with the other ones to perform its specific job so that homeostasis is maintained and the six functions of living organisms are properly carried out. The cytoplasm's main job is to transport materials from one part of the cell to another so they can be used by specific structures.
Most cells have a specific set of organelles inside its cytoplasm to carry out its main functions. Each organelle must coordinate with the other ones to perform its specific job so that homeostasis is maintained and the six functions of living organisms are properly carried out. The cytoplasm's main job is to transport materials from one part of the cell to another so they can be used by specific structures.
Nutrients, fluids, and/or wastes to be disposed of are stored in small sacklike structures called vacuoles within the cell.
In active transport a vacuole can contract to squeeze waste materials out of the cell or ingest them. The cell membrane also recognizes chemical signals or other stimuli from its environment. It reacts appropriately to these stimuli to maintain homeostasis, to produce the needed amino acids for protein production, to move, to reproduce, and to perform other functions necessary for life.
Humans are an example of a complex multicellular organism. We have many systems made of specialized cells, tissues, and organs, including systems for digestion, respiration, reproduction, circulation, excretion, movement, and coordination. These systems interact to perform the functions of a living thing and to balance our internal environment. As complex multicellular organisms, humans possess a diversity of control mechanisms that detect deviations and make corrective actions to prevent disruptions in our systems that may result in a corresponding imbalance in homeostasis.
The circulatory or cardiovascular system carries oxygen and nutrients to each cell in the body and takes away carbon dioxide and other wastes. The main organ of the circulatory system is the heart, which beats about once every second to pump blood throughout the body. Blood travels through blood vessels or tubes called arteries. The arteries branch into ever-smaller vessels called capillaries, which surround all of the other tissues of the body. Blood drains back to the heart to be repumped through other vessels called veins. A second set of arteries and veins bring blood to and from the lungs.
Blood is actually a liquid called plasma that's filled with specialized cells. Red blood cells contain a protein called hemoglobin. Oxygen molecules cling to hemoglobin so that it can be transported to each cell in the body.
White blood cells are really hunter cells - they circulate throughout your body and attack any foreign invaders that may have entered, whether through a cut, your lungs, or your stomach. Some white blood cells engulf and destroy bacteria or release chemicals called antibodies. Antibodies are part of the body's immune system; they're specific proteins your blood produces to fight off a certain bacteria or other invader similar to one it's fought off before. Remember the last time you had to get a shot? We sometimes immunize ourselves, or get injected with dead or weakened cells of a specific bacteria, to get our blood to create the correct antibodies to fight off that invader, without it being able to harm us. Immunization is used to protect us from deadly diseases like smallpox.
Also in the blood are tiny pieces of cells called platelets. If your body has a cut or other injury, platelets migrate to that location, clump together, and close the wound. They then release chemicals that form clots to plug the wound, stop the bleeding, and begin the healing process.
Also in the blood are tiny pieces of cells called platelets. If your body has a cut or other injury, platelets migrate to that location, clump together, and close the wound. They then release chemicals that form clots to plug the wound, stop the bleeding, and begin the healing process.
The skeletal and muscular systems work together with the nervous system to allow the body to move. The skeletal system consists of 206 bones, responsible for supporting your body. Specialized cells in the bones contain minerals that make them rigid. Bones are held together by thick elastic bands called ligaments and are connected to muscles by fibers called tendons. Joints are found where two bones meet, like the ball and socket joint in your shoulder that allows your arm to rotate around. In each knee, a hinge joint allows your lower leg to move so you can walk. But bones wouldn't go anywhere on their own. They're moved by the muscular system - skeletal muscles in particular. By contracting and relaxing in pairs, these muscles allow a bone to move up or down. But they too don't move on their own, but because of messages sent to them through the nervous system. Because they only move when we want to them to, they are called voluntary muscles. Involuntary muscles, on the other hand, work automatically, like the cardiac or heart muscles which beat every second of your life, and the smooth muscle found in your digestive tract's blood vessels.
Your nervous system is ultimately responsible for your body's muscle movement, coordination, and control. The central nervous system is based in your brain and spinal cord. Extending throughout your body from there is the peripheral nervous system, which consists of specialized nerve cells, or neurons, that process and transfer incoming and outgoing messages. All of your body's senses are connected to the brain by bundles of nerve cells that allow you to hear, see, feel, smell, taste, and respond to environmental impulses.
Closely connected to the nervous system is the endocrine system, a series of glands located throughout your body. This system secretes chemical substances called hormones that tell various organs what to do. For example, the adrenal gland secretes adrenaline whenever the body senses danger, which immediately causes the heart, lungs, and muscles to react, giving you a surge of strength to run from or fight off the danger. Hormones are also important in regulating many body functions involved with maintaining homeostasis.
The respiratory system supplies oxygen and removes carbon dioxide from the blood. During respiration, cells use oxygen to release the energy stored in food. When you breathe, a large muscle called the diaphragm contracts and expands, forcing air in and out of two large sacs called lungs, just behind your ribs. Each lung is filled with tiny sacs called alveoli, in which blood exchanges carbon dioxide for oxygen. The circulatory system then brings the oxygen-rich blood to every cell in your body.
The organs of the digestive system are responsible for the breakdown of food, which produces molecules that can be absorbed and transported to each cell in your body. The process begins with mechanical digestion, or the chewing of food by your teeth, then continues as chemical digestion, in which enzymes break nutrients down into smaller molecules that your body can use. Digestion therefore starts in your mouth and continues in your digestive tract. As an example, let's examine your breakfast. After you chew your cereal, it passes into your esophagus and then your acid-filled stomach. Along the way, enzymes are secreted to break the food down, then it all passes into the small intestine, where it mixes with bile from the liver and juices from the pancreas. Bile, stored in a small sac called the gallbladder, helps to digest fats; the pancreas helps neutralize stomach acids before the food moves on. The liver, meanwhile, breaks down toxic substances and creates cholesterol for cell membranes. Still in the small intestine, your broken-down breakfast passes through tiny fingerlike projections called villi; here, nutrients are absorbed and then passed into the blood stream for delivery to other cells in the body. What can't be absorbed is pushed into the large intestine, where water is absorbed from the remaining food. What's left is finally squeezed down to the rectum and expelled through the anus as waste material called feces. Certainly you know less scientific terms for that stuff.
The excretory system works with the circulatory system to dispose of waste materials, liquids, and excess heat energy from the body. The most important organ in this system is the kidney, which filters out waste materials from the blood. These are then collected in the bladder and removed as urine. Your skin also eliminates excess fluid through sweating, a process that cools the body as well when the sweat evaporates.
Many more systems exist in your body to keep you alive and functioning. The reproductive system produces either male or female sex cells. Your skin is an organ that serves a wide range of tasks: It's a barrier to infectious bacteria; it sweats to cool you off; it has nerve cells that allow you to touch and feel objects in your environment. Oh yeah - it also holds your body together.
Disease happens when there's a breakdown in one of the body's systems. It may be caused by a collapse of the body's immune system, or a malfunction due to injury, age, infection, or a shortage of a necessary nutrient. Disease represents a lack of homeostasis in the body or cells in one or more organs, and threatens your body's ability to carry out one or more of the six functions of all living things.
Disease happens when there's a breakdown in one of the body's systems. It may be caused by a collapse of the body's immune system, or a malfunction due to injury, age, infection, or a shortage of a necessary nutrient. Disease represents a lack of homeostasis in the body or cells in one or more organs, and threatens your body's ability to carry out one or more of the six functions of all living things.
Muscles actually do two things: contract and relax. They generally work together in pairs to pull a bone up or down. For example, hang your right arm down at your side and place your left hand on your arm midway between your elbow and shoulder. Now slowly move your hand up so your right arm bends at the elbow. You'll start to feel a bulge where your hand is holding your arm. These are your bicep muscles contracting.
Now slide your left hand around the back of your arm and lower it back to your side. It won't bulge as much because it's a smaller muscle, but you will feel your triceps muscle contract.
Next, kneel down, then slowly stand up and kneel again. Try to locate the hamstring and quadriceps muscles, two of the largest muscles in your body, which power your legs. They are located between your hips and knees in the back and front of your leg.
Now slide your left hand around the back of your arm and lower it back to your side. It won't bulge as much because it's a smaller muscle, but you will feel your triceps muscle contract.
Next, kneel down, then slowly stand up and kneel again. Try to locate the hamstring and quadriceps muscles, two of the largest muscles in your body, which power your legs. They are located between your hips and knees in the back and front of your leg.
Scientists have sent space probes to land on the moon and several planets in our solar system, looking to answer a big question: "Is there life anywhere else in our solar system?" So far, we have not found any, but that may be because we haven't looked in the right places yet. Most of the places where we have landed were missing some of the conditions needed for life, whether water, a breathable atmosphere, or a source of energy.
One of Jupiter's moons, Europa, is believed to have most of the conditions necessary for life to exist. If we land a space probe on Europa and find moving objects on the surface, what six characteristics must these objects have if we are to agree that they are alive?
One of Jupiter's moons, Europa, is believed to have most of the conditions necessary for life to exist. If we land a space probe on Europa and find moving objects on the surface, what six characteristics must these objects have if we are to agree that they are alive?
Have you ever been sick with a virus? A virus is a microscopic particle that invades a living organism, uses it to reproduce, and then destroys it. There are possibly billions of types of viruses out there, found in many different shapes, but all of them are composed of genetic material covered by a protein shell. When a virus enters a host cell, it injects its DNA into the host; instead of reproducing itself, the host reproduces more viruses. Without a host, however, a virus cannot reproduce itself. Why aren't viruses considered living things?
Your cardiovascular system is one of the most important systems for the overall health of your body. While a wide range is normal, the average person's heart pumps 76 times per minute when resting. Individuals with a healthy heart and lungs generally have a heart rate on the slow side of this, because their heart and lungs work very efficiently. So what's your pulse like? To find out, have a friend hold a watch with a second hand. Take two fingers and press gently on the side of your neck just below your jaw. When you can feel something beating, you've found your carotid artery, which brings blood from the heart to the head and pulses with each heartbeat. Have your friend time you for one minute while you count the beats of your heart.
Next, run around the room (or yard) for two minutes, then take your pulse again. How did it change? Can you guess why? (Hint: What is the function of the cardiovascular system? What did your muscles do when you ran around?)
Next, run around the room (or yard) for two minutes, then take your pulse again. How did it change? Can you guess why? (Hint: What is the function of the cardiovascular system? What did your muscles do when you ran around?)
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