Cells (Parts and Functions), Plant and Animal Cell | Grade 7 Science DepEd MELC Quarter 2 Module 4

Summary

This educational video script explores the fundamental unit of life, the cell, highlighting its key components and functions. It explains the cell's basic structures including the cell membrane, nucleus, and cytoplasm, and delves into the roles of various organelles like mitochondria, ribosomes, endoplasmic reticulum, and the Golgi apparatus. The script distinguishes between plant and animal cells, noting differences such as the presence of chloroplasts in plants and centrosomes in animals. It also touches on the cell's waste management through lysosomes and the storage function of vacuoles, providing a comprehensive foundation on cellular biology.

Takeaways

• 🔬 The cell is the first and most basic level of biological organization, serving as the fundamental unit of life.
• 👨‍🔬 Robert Hooke was the first to observe cells as microscopic structures, coining the term 'cell' from the Latin 'cellulae' meaning small rooms.
• 🧬 Cells are composed of organelles, which are tiny structures that perform specific functions, akin to little organs within the cell.
• 🌿 Plant and animal cells share common structures such as the cell membrane, nucleus, and cytoplasm, but they also have distinct differences.
• 🛡️ The cell membrane, or plasma membrane, acts as a protective barrier and regulates the passage of materials into and out of the cell.
• 🧠 The nucleus is often referred to as the 'brain' of the cell, containing DNA and directing cellular activities.
• ⚡️ Mitochondria are known as the 'powerhouses' of the cell, generating energy in the form of ATP.
• 🔠 Ribosomes, containing RNA and proteins, are responsible for protein synthesis within the cell.
• 🚛 The endoplasmic reticulum (ER) comes in two forms: smooth ER involved in lipid synthesis and rough ER involved in protein production and transport.
• 📦 The Golgi apparatus is responsible for modifying, packaging, and transporting proteins and lipids to their destinations.
• 🗑️ Lysosomes contain enzymes that digest waste and worn-out cell parts, acting as the cell's waste disposal system.

Q & A

What is the first level of biological organization discussed in the video?

The first level of biological organization discussed in the video is the cell.

Who was the first person to observe cells as microscopic structures?

The British scientist Robert Hooke was the first person to observe cells as microscopic structures.

What does the term 'cell' originate from, and why was it used by Robert Hooke?

The term 'cell' originates from the Latin word 'cellulae,' which means small rooms. Robert Hooke used the term because the tiny rooms he observed in cork under a microscope resembled small empty rooms.

What are organelles and why are they important?

Organelles are tiny organs within a cell that perform specific functions. They are important because they are responsible for the various life-sustaining processes within the cell.

What are the three basic structures common to most cells?

The three basic structures common to most cells are the cell membrane, nucleus, and cytoplasm.

What is the function of the cell membrane?

The cell membrane, also known as the plasma membrane, encapsulates the cell's contents, protects it from the outside environment, and controls the movement of materials in and out of the cell.

What is the role of the nucleus in a cell?

The nucleus houses DNA, which carries genetic instructions, and is considered the 'brain' of the cell because it directs all cellular activities.

What is the function of mitochondria within a cell?

Mitochondria are known as the powerhouse of the cell because they produce adenosine triphosphate (ATP), which is the cell's energy source.

How do ribosomes contribute to protein production in a cell?

Ribosomes, containing RNA and specific proteins, are directly involved in the manufacture of proteins within the cell.

What is the primary function of the Golgi apparatus?

The Golgi apparatus is responsible for transporting, modifying, and packaging proteins and lipids into vesicles for delivery to targeted destinations within the cell.

What is the difference between plant and animal cells in terms of vacuoles?

Plant cells have a large singular vacuole used for storage and maintaining cell shape, while animal cells have many smaller vacuoles.

Why do plant cells have a cell wall and what is its function?

Plant cells have a cell wall that surrounds the cell membrane, providing structural support and maintaining the cell's shape, allowing the plant to remain strong and stand upright.

What is the role of the centrosome in animal cells?

The centrosome is a microtubule organizing center in animal cells that plays a role in cell division, particularly in the replication and separation of chromosomes during cell division.

Outlines

00:00

🔬 Introduction to Cells

This paragraph introduces the concept of cells as the first level of biological organization. It emphasizes the importance of microscopes for observing cells and credits Robert Hooke as the first person to observe cells as microscopic structures. The term 'cell' originates from Hooke's observation of cork cells resembling small rooms. The paragraph explains that cells are composed of organelles, which are like tiny organs with specific functions. It outlines the basic structures common to most cells: the cell membrane, nucleus, and cytoplasm. The cell membrane is described as a protective barrier that controls the passage of materials in and out of the cell. The nucleus is depicted as the 'brain' of the cell, containing DNA and directing cellular activities. The cytoplasm is presented as the gel-like substance where organelles reside. The paragraph also introduces the concept of organelles and their role in cell functions.

05:02

🌿 Organelles and Their Functions

This section delves into the functions of various organelles within a cell. It describes the mitochondrion as the 'powerhouse' of the cell, responsible for producing energy in the form of ATP. Ribosomes are introduced as tiny organelles that manufacture proteins using RNA and specific proteins. The endoplasmic reticulum (ER) is explained as having two forms: smooth and rough, with the latter involved in protein synthesis and transportation. The Golgi apparatus is highlighted for its role in modifying, packaging, and transporting proteins and lipids. Lysosomes are mentioned as the waste disposal system of the cell, digesting waste and damaged cell parts. Lastly, the vacuole is described as a space within the cell that stores various molecules, including water and food material. The paragraph also contrasts plant and animal cells, noting that while they share some organelles like mitochondria, plant cells have unique structures like chloroplasts for photosynthesis and a cell wall for support.

10:04

🌱 Differences Between Plant and Animal Cells

This paragraph summarizes the differences between plant and animal cells. It points out that plant cells have a large central vacuole for storage and maintaining cell shape, whereas animal cells have many smaller vacuoles. Plant cells contain chloroplasts for photosynthesis and a cell wall for support, which are absent in animal cells. Lysosomes are less common in plant cells but are found in almost every animal cell, reflecting the different digestive needs of the two cell types. Animal cells possess a centrosome, which is absent in plant cells. The centrosome's role in cell division is discussed, although its exact function remains unclear. The paragraph concludes with a table comparing the structures found in plant and animal cells, reinforcing the distinctions and similarities between them.

Keywords

💡Cell

A cell is the fundamental unit of life and the primary focus of the video. It is defined as the smallest structural and functional unit of living organisms, consisting of an organized structure of organelles enclosed within a membrane. In the script, cells are described as having common structures like the cell membrane, nucleus, and cytoplasm, which are essential for their function. The video emphasizes the cell's role as the basic building block of all living things, highlighting its importance in biological organization.

💡Organelles

Organelles are specialized subunits within a cell that perform specific functions necessary for the cell's survival. The term 'organelle' is used in the script to describe tiny organs within the cell, each with a unique role. Examples from the script include mitochondria, which are known as the powerhouse of the cell, and ribosomes, which are involved in protein synthesis. The video explains that organelles are essential for the cell's ability to carry out its functions, illustrating their importance in the cell's overall operation.

💡Cell Membrane

The cell membrane, also known as the plasma membrane, is a biological membrane that separates the interior of the cell from its external environment. It is described in the script as a protective barrier that controls the movement of substances in and out of the cell. The cell membrane is composed of a phospholipid bilayer, which is crucial for maintaining the cell's integrity and regulating its interactions with the environment. The video emphasizes the cell membrane's role in protecting the cell and facilitating selective transport.

💡Nucleus

The nucleus is a membrane-bound organelle found in eukaryotic cells that contains the cell's genetic material. In the script, the nucleus is referred to as the 'brain of the cell' because it directs all cellular activities. It houses DNA and various proteins, including the nucleolus, which is involved in ribosome production. The video highlights the nucleus's central role in storing and regulating genetic information, which is essential for the cell's function and reproduction.

💡Cytoplasm

Cytoplasm is the jelly-like substance found within a cell, between the cell membrane and the nucleus, where all the organelles are suspended. The script describes the cytoplasm as the material that fills the cell and provides the medium for organelles to function. It is essential for the cell's ability to carry out its metabolic processes and maintain its structure. The video emphasizes the cytoplasm's role in supporting the cell's internal environment and facilitating the movement and interaction of organelles.

💡Mitochondrion

Mitochondria, the plural form of mitochondrion, are large organelles found in eukaryotic cells and are often referred to as the 'powerhouse of the cell.' The script explains that mitochondria are responsible for producing adenosine triphosphate (ATP), the cell's primary energy source. The video underscores the importance of mitochondria in cellular respiration and energy metabolism, highlighting their role in converting nutrients into usable energy for the cell.

💡Ribosomes

Ribosomes are small, dot-like organelles found in the cytoplasm of cells, composed of ribonucleic acid (RNA) and proteins. As described in the script, ribosomes are directly involved in the synthesis of proteins, translating the genetic code from messenger RNA (mRNA) into polypeptide chains. The video highlights ribosomes as essential components of protein production, illustrating their role in translating genetic information into functional proteins.

💡Endoplasmic Reticulum (ER)

The endoplasmic reticulum (ER) is a network of membranous tubules and sacs found within the cytoplasm of eukaryotic cells. The script distinguishes between two types of ER: smooth ER, which lacks ribosomes and is involved in lipid synthesis, and rough ER, which has ribosomes and is involved in protein synthesis and transport. The video emphasizes the ER's role in the cell's protein and lipid production, highlighting its importance in cellular metabolism and structure.

💡Golgi Apparatus

The Golgi apparatus is an organelle found in eukaryotic cells, responsible for modifying, sorting, and packaging proteins and lipids into vesicles for transport to their final destinations. The script describes the Golgi apparatus as being located near the endoplasmic reticulum and the cell nucleus. The video highlights the Golgi apparatus's role in the cell's secretory pathway, emphasizing its importance in the processing and distribution of cellular products.

💡Lysosomes

Lysosomes are membrane-bound organelles containing digestive enzymes that break down waste materials and cellular debris. The script refers to lysosomes as the 'waste disposal system of the cell,' responsible for digesting obsolete or unused materials in the cytoplasm. The video emphasizes lysosomes' role in cellular housekeeping, illustrating their importance in maintaining cellular health by removing damaged or unnecessary components.

💡Vacuole

A vacuole is a membrane-bound organelle found in plant and some animal cells, serving as storage for various molecules, including water, nutrients, and waste products. The script describes vacuoles in plant cells as large and singular, while in animal cells, they are smaller and more numerous. The video highlights the role of vacuoles in maintaining cell turgor pressure and osmotic balance, emphasizing their importance in cellular storage and maintaining cell shape.

Highlights

The cell is the first level of biological organization and is considered the basic unit of life.

Robert Hooke was the first to observe cells as microscopic structures and coined the term 'cell' from the Latin word 'cellulae' meaning small rooms.

Cells are composed of organelles, which are tiny organs that perform specific functions within the cell.

The cell membrane, or plasma membrane, serves as a protective barrier and regulates the movement of substances in and out of the cell.

The nucleus contains DNA, which carries genetic instructions, and is often referred to as the 'brain' of the cell.

Cytoplasm is a jelly-like substance that houses organelles and is found between the cell membrane and the nucleus.

Mitochondria are known as the powerhouse of the cell, producing energy in the form of ATP.

Ribosomes, containing RNA and specific proteins, are responsible for protein synthesis within the cell.

The endoplasmic reticulum (ER) comes in two forms: smooth and rough, with the rough ER involved in protein synthesis and the smooth ER in lipid synthesis.

The Golgi apparatus is responsible for the modification, packaging, and transport of proteins and lipids in vesicles to their destinations.

Lysosomes contain enzymes that digest waste and damaged cell parts, acting as the cell's waste disposal system.

Vacuoles are membrane-bound spaces that store various molecules, including water, enzymes, and food material, depending on the cell type.

Plant cells and animal cells share common organelles like the nucleus and mitochondria but have differences due to their distinct functions.

Plant cells contain chloroplasts for photosynthesis, which animal cells lack as they obtain energy from food.

Plant cells have a large central vacuole for storage and maintaining cell shape, unlike animal cells which have many smaller vacuoles.

Plant cells are surrounded by a cell wall, providing structural support and protection, which is absent in animal cells.

Lysosomes are more prevalent in animal cells for digesting food, while plant cells typically do not have them due to their cell walls.

Animal cells contain a centrosome, which plays a role in cell division, a feature not found in plant cells.

Transcripts

[Music]

hi

there in the previous lesson we talked

about the levels of biological

organization

in this video we will discuss about the

first level of biological organization

which is the cell by the way if you

still haven't watched the previous

lesson

you can pause this video and watch that

one first to better understand your

lesson today

we learned that a microscope enables us

to see small things because of its

ability to magnify

the first person to observe cells as

microscopic structures

was the british scientist robert hook in

fact

he was the person who gave styles

turning

[Music]

when robert hook carefully examined a

very thin slice of cork

he thought the close-up view resembled

small empty rooms

he referred to these tiny rooms the

cells from the latin word cellulae

which means small rooms a cell is made

up of tiny organs called organelles that

perform

specific functions they are called

organelles because they are like

little organs that have its own function

from what we discussed in the previous

video we learned that the cell is the

basic unit of life

there are two kinds of cells the plant

cell

and the animal cell we will be

differentiating both types of cells

but for now let's talk about its parts

and functions first

while cells differ in size and shape

most of them have common structures

the cells of animals plants and related

organisms

have three basic structures the cell

membrane

nucleus and cytoplasm

the cell membrane also known as the

plasma membrane

encapsulates the contents of the cell it

is like a fence

or acts as a gatekeeper to protect the

cell from the outside environment

it also controls what materials can go

in and out of the cell

the cell membrane is made up of two

layers of phospholipids

or phospholipid bilayer

the nucleus houses deoxyribonucleic acid

or dna for short which is the hereditary

material that carries genetic

instructions

in all living things it also houses

various proteins

and the nucleolus it is considered as

the brain of the cell

because it directs all the activities of

the cell

the cytoplasm is where all the

organelles are located

and has a jelly-like fluid it is the

material between the cell membrane

and the nucleus alright so let's move on

to the organelles

the first organelle we're going to

discuss is the mitochondrion

or mitochondria in pleural form

it is one of the largest organelles

within a cell

it is also known as the powerhouse of

the cell

since it is where the energy of the cell

the adenosine triphosphate

or atp for short is produced

next we have the ribosomes ribosomes are

tiny organelles like dots that contain

ribonucleic acid

or rna and specific proteins within the

cytoplasm

within the cell ribosomes are directly

involved in the manufacture of proteins

another organelle is the endoplasmic

reticulum

or er for short there are two types of

er

the smooth er and the rough er

the smooth er is named so because it

lacks ribosomes in its surface

however the rough er is the opposite

since the rough er has ribosomes it is

involved in the manufacture of proteins

in the cell

the rough er also helps in the

transportation of proteins

on the other hand the smooth er is

involved in the synthesis of lipids

like phospholipids which are used to

build the cell membrane

other functions of the smooth er include

metabolism of carbohydrates enzyme

production in the liver

and contraction of muscle cells in the

muscles

another organelle is the golgi apparatus

it is responsible for transporting

modifying

and packaging proteins and lipids into

vesicles for delivery to targeted

destinations

it is located in the cytoplasm next to

the endoplasmic reticulum

and near the cell nucleus while many

types of cells contain

only one or several golgi apparatus

plant cells can contain hundreds

did you know that cells also produce

waste

in the cytoplasm structures called

lysosomes contain

chemicals that digest waste and worn out

or damaged

cell parts lysosomes act as the waste

disposal system of the cell

by digesting obsolete or unused

materials in the cytoplasm

thus lysosomes are also called suicidal

bags of the cell

[Music]

lastly we have the vacuole a vacuole may

be described

as a space inside a cell that does not

contain

cytoplasm it is surrounded by a membrane

and filled with fluid

vacuoles store various molecules

including enzymes

waste products of the cell water and

even

food material depending on the type of

cell

both plant and animal cells contain

membrane-bound

organelles like the nucleus in

mitochondria

however plant cells and animal cells do

not look exactly the same

or have all of the same organelles since

each of them

have different needs so how

are plant and animal cells similar or

different

why do plant and animal cells have

differences

plant and animal cells differ because

they have to perform

different functions

both animal and plant cells have

mitochondria

but only plant cells have chloroplast

plants don't get their sugar from eating

food so they need to make sugar with the

help of the sunlight

this process known as photosynthesis

takes place in the chloroplast once the

sugar is made

it is then broken down by the

mitochondria to make energy for the cell

because animals get sugar from the food

they eat

they do not need chloroplasts just

mitochondria

both plant and animal cells have

vacuoles

a plant cell contains a large singular

vacuole

that is used for storage and maintaining

the shape of the cell

in contrast animal cells have many

smaller vacuoles

not seen in this illustration is the

vacuole of the animal cell

both plant and animal cells have a cell

membrane

but only plant cells have a cell wall

in plant cells the cell wall surrounds

the cell membrane

this gives the plant cell its box-like

shape

this also allows plants to remain strong

and stand

upright even if they grow to great

heights

lysosomes are found in nearly every

animal cell

they are common in animal cells because

when animal cells take in or absorb

food they need the enzymes found in

lysosomes to digest

and use the food for energy on the other

hand

lysosomes are not commonly found in

plant cells

lysosomes are not needed in plant cells

because they have cell walls that are

tough enough to keep

large or foreign substances that

lysosomes would usually digest

out of the cell

[Music]

lastly we have the centrosome the

centrosome is a microtubule

organizing center found near the nuclei

of

animal cells it contains a pair of

centrioles

two structures that lie perpendicular to

each other

the centrosome replicates itself before

a cell divides

and the centrioles appear to have some

role in pulling the duplicated

chromosomes

to opposite ends of the dividing cell

however

the exact function of the centrioles in

cell division isn't clear

because cells that have had the

centrosome removed can still divide

and plant cells which lack centrosomes

are capable of cell division

all right as a recap here are all the

organelles that we

talked about the three basic components

of the cell

are the cell membrane nucleus

and cytoplasm within the cytoplasm

are the organelles which are the

mitochondria

ribosomes smooth and rough endoplasmic

reticulum

golgi apparatus lysosomes

and not seen in the illustration of the

animal cell

is the vacuole those are the very basic

organelles of the cell

now here is a table comparing the

structures found in the plant and animal

cell

plant cells have a large singular

vacuole

while animal cells have many smaller

vacuoles

plant cells have chloroplasts in a cell

wall

while animal cells don't lysosomes are

rarely present

in plant cells but are present in almost

every animal cell

and lastly animal cells have a

centrosome

while plant cells do not alright

that's all for now we will be talking

about sexual and asexual reproduction in

our next lesson

see you on our next video and don't

forget to keep your minds

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