Organelles and cells

What is the function of the cell membrane?

What is the function of the cell membrane?

It allows movement in and out of cells as it is semi permeable

What is the function of the nucleus?

It houses DNA and controls what the cell makes

What is the function of the cytoplasm

It is where chemical reactions take place

What is the function of a mitochondrion?

It carries out aerobic respiration to produce ATP

What is ATP needed for?

Active transport, muscle contraction, nerve impulse transmission

Label the nucleus

Label the smooth endoplasmic reticulum

Label the cell wall

Label the Golgi apparatus

Label the lysosome

Label the rough endoplasmic reticulum

Label the cytoplasm

Label the ribosome

Label the mitochondria

Label the nucleolus in the structure of the nucleus

Label the nuclear envelope in the structure of the nucleus

Label chromatin in the structure of the nucleus

Label the nuclear pore in the structure of the nucleus

Label the membrane in the rough endoplasmic reticulum

Label the fluid in the rough endoplasmic reticulum

Label the ribosomes in the rough endoplasmic reticulum

Label the membrane in the smooth endoplasmic reticulum

Label the fluid in the smooth endoplasmic reticulum

Label the membrane in the Golgi apparatus

Label the vesicle in the Golgi apparatus

Label the fluid in the Golgi apparatus

Label the cristae in the mitochondrion

Label the outer mitochondrial membrane in the mitochondrion

Label the inner mitochondrial membrane in the mitochondrion

Label the circular DNA in the mitochondrion

Label the ribosomes in the mitochondrion

Label the inter membrane space in the mitochondrion

Label the matrix in the mitochondrion

What does the nuclear pore do in the nucleus?

Allows messenger RNA and ribosomal RNA out and nucleotides in

What does chromatin do in the nucleus?

Loose form of DNA

What does the nuclear envelope do in the nucleus?

It’s a double membrane made of 2 phospholipid layers that separates the nucleus from the cytoplasm. It has holes which are the nuclear pores.

What does the nucleolus do in the nucleus?

Produces ribosomal RNA (rRNA) which makes up part of the structure of ribosomes

What is the overall function of the nucleus?

It contains DNA which codes for the sequence of amino acids in proteins, the DNA is wrapped around histones to make it more compact

What are ribosomes?

Very small organelles which are often drawn as dots, they are free in the cytoplasm or attached to the rough end plastic reticulum.

What is the size of ribosomes which are in the cytoplasm or RER?

80s

What is the function of ribosomes?

They carry out the first stage of protein synthesis, this is where the amino acids are joined to make a polypeptide chain

What is the rough endoplasmic reticulum?

A collection of membranes which are filled with fluid, ribosomes are attached to the surface of the membranes

What is the function of the RER?

The ribosomes on the surface of the fluid filled membrane carry out protein synthesis, the polypeptides that are made on the ribosomes are packaged into vesicles which transport the polypeptide to the Golgi apparatus

What is the smooth endoplasmic reticulum?

Consists of fluid-filled membranes, no ribosomes unlike the rough endoplasmic reticulum

What is the function of the SER?

It is involved in synthesising and transporting lipids which are needed for cell membranes

What is the difference between the RER and the SER?

RER= synthesising and transporting proteins

SER= synthesising and transporting lipids

What is the Golgi apparatus?

Polypeptide chains which are made at the RER are transported to the Golgi apparatus, it modifies and folds it. It completes the production of the protein

What is the function of the Golgi apparatus?

It folds the polypeptide, modifies it and adds some extra molecules such as carbohydrates or lipids - it completes the production of proteins. The protein is then packaged into a vesicle which transports the protein to the cell membrane where it can be released through exocytosis, it can then travel to other cells or other parts of the body

What is a lysosome?

A membrane-bound vesicle which contains digestive enzymes, they have no clear internal structure

What are the 2 functions of lysosomes?

1. They are important in the immune response - when a pathogen such as bacteria is engulfed by a WBC in phagocytosis, the digestive enzymes digest the pathogen

2. It breaks down worn out parts of the cell like old organelles that don’t function properly anymore

QUESTION: describe how the ribosomes, RER and Golgi apparatus work together

• In the ribosomes which can be found in the cytoplasm or the surface of the RER, amino acids are joined together to make a polypeptide

• The polypeptide is transported to the Golgi apparatus through vesicles that pinch off the RER

• In the Golgi apparatus, the polypeptide is modified which means it could be folded to give it a specific shape or a molecule could be added

• The final protein is packaged into a secretary vesicle which transports the protein to the cell membrane

What is the function of the mitochondria?

They carry out aerobic respiration to produce ATP which is an immediate and universal source of energy

What is the purpose of cristae folding in the mitochondria?

Provides a larger surface area for the attachment of enzymes, this leads to an increased rate of aerobic respiration which means more ATP is produced

What is a vacuole?

An enclosed space filled with cell sap which contains substances such as sugars, salts, water and enzymes. The membrane is called the tonoplast which controls what does in and out

What is the function of a vacuole?

It helps the plant from wilting, water is drawn into the vacuole by osmosis which maintains a high pressure inside - this keeps the plant cells turgid

Label the starch grain in the vacuole

Label the storm in the vacuole

Label the double membrane in the vacuole

Label the circular DNA in the vacuole

Label the lamellae in the vacuole

Label the Ribosomes and state the size in the vacuole

Label the thylakoid in the vacuole

What is the function of the starch grain in the vacuole?

Makes sugar and stores starch grains

What is a granum in the vacuole?

A stack of thylakoids

What is the function of the stroma in the vacuole?

Thick fluid which surrounds the objects in the vacuole, it contains enzymes needed for photosynthesis

What is the lamellae in the vacuole?

Thylakoid membranes that extend between the grana

What is the function of the chloroplast?

Photosynthesis - adapted to absorb sunlight and carry out photosynthesis to produce glucose and some ATP

What is the plasmodesma?

A stream of cytoplasm that connect 2 adjacent plant cells

What is the function of the plasmodesma?

It allows water and dissolved molecules to move between cells in a plant

What is the cell theory?

• All living organisms are composed of one or more cells

• Cells are the basic unit of life

• Cells can only arise from pre-existing cells