Cell Components

Animal and plant cells

Cytoplasm

A jelly-like substance that fills the cell and holds organelles in place.

Nucleus

The control center of the cell that contains genetic material.

Metabolism

The biochemical processes that occur within cells, involving energy production and substance transformation.

Homeostasis

The ability of cells to maintain stable internal conditions despite external changes.

Prokaryotic Cells

Simple cells without a nucleus, such as bacteria.

Eukaryotic Cells

More complex cells with a nucleus and organelles, such as plant and animal cells.

Chloroplasts

Organelles in plant cells that enable photosynthesis, converting sunlight into glucose.

Vacuole (in Plant Cells)

A large central vacuole that maintains turgor pressure and stores materials.

Lysosomes

Organelles containing digestive enzymes that break down waste materials and cellular debris in animal cells.

Endoplasmic Reticulum (ER)

A network of membranes involved in protein (rough ER) and lipid (smooth ER) synthesis.

Golgi Apparatus

Modifies, sorts, and packages proteins and lipids within the cell for transport.

Centrioles

Structures involved in organizing microtubules during cell division and forming spindle fibers.

Cytoskeleton

A network of fibers that help maintain cell shape and facilitate movement within the cell.

What's in the nucleus ?

The nucleus contains the cell's genetic material, including DNA, and is responsible for regulating gene expression and cell division.

-nuclear envelope
-nucleolus
-chromatin
-nuclear pore

What's the function of a nucleus?

The nucleus serves as the control center of the cell, regulating gene expression, storing genetic information, and coordinating cell activities such as growth, metabolism, and reproduction.

-site of dna replication and transcription
-site of ribosome synthesis
-contains genetic code
-contains dna to direct protein synthesis to control metabolic activities through protein enzymes

What's the function of a nuclear envelope

It's a double membrane that protect the nucleus from damage in the cytoplasm

What are nuclear pores?

holes in the nuclear envelope where things can pass into and out of the nucleus.

What are chromatins ?

Dna associates with proteins called his tones to form chromatin which coils and condensed to form chromosomes

What's the function of a nucleolus?

An area within the nucleus that's responsible for protein synthesis. It is composed of ribosomal RNA which is then combined with proteins to form ribosomes for protein synthesis

What is the nucleoplasm?

The granular, jelly-like material that makes up the bulk of the nucleus

What's the function of mitochondria?

Site of the final stages of cellular respiration where the energy stored in the bonds of organic molecules is made available for the cell to use by the production of ATP during aerobic

What's mitochondrial (mt )DNA?

Mitochondrial DNA is the genetic material found in mitochondria, distinct from nuclear DNA, that is inherited maternally and encodes essential proteins for mitochondrial function.

What does mtDNA do?

contains genes which code for tRNA, and makes enzymes for cellular respiration

Describe the membrane of mitochondria?

Has a double membrane
-inner membrane is highly folded to form structures called cristae
-membrane forming the cristae contains enzymes used in aerobic respiration

What's cristae

Inner membrane of mitochondria

What's the matrix ?

Fluid interior of mitochondria

What are vesicles ?

membranous sacs that are used to transport or store materials in the cell

What are the two types of vesicles?

transport and secretory

What's the function of a vesicle ?

Transport and storage

Describe the structure of a vesicle

A small fluid-filled sac in the cytoplasm, surrounded by a single membrane.

What's a lysosome ?

Specialised form of a vesicle that contains hydrolytic enzymes that are responsible for breaking down waste material in cells and organelles

What's the plasma membrane made off?

Lipids and proteins-phospholipid bilayer

What's the function of a plasma membrane?

-Regulates the movement of substances
-has receptor molecules which allows it to respond to chemicals

What does the plasma membrane have ?

Receptor molecules to respond to chemicals

What's the cytoskeleton ?

Network of fibres for the shape and stability of a cell. Holds the organelles in place and it controls cell movements and the organelles movement

What are microfilaments ?

Contractile fibres made up of a protein called actin

What's the function of microfilaments?

Responsible for cell movement and also cell contraction during cytokinesis

What are microtubules?

Globular tubulin proteins polymerise to form tubes that are used to form a scaffold-like structure that determines the shape of a cell

What's the function of microtubules ?

-determines the shape
-acts as tracks for the movement of organelles
-has spindle divers which has a role in the physical segregation of chromosomes

What are intermediate filaments?

Fibres which give mechanical strength to cells and help maintain integrity

What's the function of intermediate filaments?

Mechanical strength

What are centrioles?

A component of the cytoskeleton made up of bundles of microtubules

What do two associated centrioles form?

The centrosome- which is involved in the assembly and organisation of the spindle fibres and organisation of chromosomes in cell division

What's the function of centrioles in organisms with flagella and cillia?

Positions the flagella and cillia

What is flagella?

Sensory organelle detecting chemical changes in the cells environment

What's the function of a flagella?

Movement amd sensory organs to detect chemical stimuli

What are cillia?

hair-like extensions that protrude from some cell types

Where can stationary cillia be found?

On the surface

What's the function of mobile cilia?

Beat in a rhythmic manner creating a current and cause fluids or objects adjacent to the cell to move

Describe the structure of cilia

9+2 arrangement of microtubules, all linked by proteins (11 microtubules total)

Do ribosomes have a membrane?

A single membrane

What are ribosmes?

Site of protein synthesis

What are ribosomes made of?

RNA and proteins

Where are ribosomes found?

free-floating in the cytosol, or bound to the rough ER or the nuclear envelope
Can also be found in the mitochondria and chloroplast

What are the two types of ribosomes?

80S and 70S

Where are 70S ribosomes found?

Prokaryotic cells, mitochondria and chloroplasts

Where are 80S ribosomes found?

eukaryotic cells (larger)

What are smooth ER?

Network of membranes enclosing flattened sacs called cisternae .It is connected to the outer membrane of the nucleus

What's the function of smooth ER?

Responsible for lipid and carbohydrate synthesis and storage

What are rough endoplasmic reticulum?

Network of membranes enclosing flattened sacs called cristernae.

What's the function of rough ER?

Synthesis and transport of proteins

What's found on the cisternae on the RER?

Ribosomes

What's the function of the RER?

transport proteins

What is the golgi apparatus?

flattened stacks that process, package, and deliver proteins and lipids from the ER

What's the function of the Golgi apparatus?

-add carbohydrates to proteins to form glycoproteins
-produce secretory vesicles
-secrete carbohydrates
-Modifies proteins and packaging them into vesicles.These may be secretory vesicles ,if the proteins are destined to leave the cell or lysosomes which stay in the cell

Whats the structure of Golgi apparatus?

Folded membranes of cisternea and does not contain ribosomes

Where do the secretory vesicles pinch off from on the Golgi apparatus?

The cisternae

What is the cellulose cell wall?

A tough, inelastic covering that is permeable to even large molecules

What the function of a cellulose cell wall?

-gives shape
-makes cells rigid as the content of the cell press against cell wall
-support to the cell and plant
-defence mechanism

What's is the structure of a cellulose cell wall?

Made of cellulose
Contains plasmodesmata

What is the fungi cell wall made of?

chitin

What's chitin?

A nitrogen containing polysaccharide

Is the cell wall permeable?

Freely permeable

What is a vacuole?

-Membrane lined sac in the cytoplasm containing cell sap.

What's the membrane of a vacuole?

Tonoplast

What's the function of the vacuole?

Maintenance of turgor as organelles push against cell wall creating a rigid framework

Is the vacuole permeable?

Semi permeable

What is a chloroplast?

A structure in the cells of plants and some other organisms that captures energy from sunlight and uses it to produce food.

Is chloroplast double membraned?

Yes

What's stroma?

Fluid enclosed in the chloroplast

What is a thylakoid?

Internal network of membranes which form flattened sacs embedded with pigment

What is a granum?

A stack of thylakoids in a chloroplast

What are the grana joined by?

Membranes called lamellae

What do the granas do?

Contain chlorophyll pigment where light dependent reaction takes place

What does the chloroplast contain?

Dna and ribosomes