Combined CELLS

Describe the structure of the nucleus

The nucelus contains genetic matieral called chromatin and histone proteins bound in the membrane. Contains one or more nucleoli. The nuclear enevelope surronds the nucleus which nuclear pores between. There is also nucleoplasm in the nucleus.

nucleus function

contain genetic material of a cell in the form of chromosomes, holds instruction for protein synthesis, essential for cell divison, controls cell activity

Nuclear enevelope

double membrane that controls material entry and exit

Nuclear pores

Nuclear pores allow molecules to move in and out. For example, mRNA moves out during protein synthesis

Nucleolus

makes ribosomes (manufactores ribosomal RNA and assembles the ribosomes)

Chromatin

made of protein and DNA. it controls cell activity

Diff between pro and euk

1. eukaryotic has membrane-bound organelles

2. prokaryotic is smaller

3. pro has smaller ribosomes

Ribosomes description and location

contains RNA and protein. it is found at cytoplasm or on rough er. Ri

ribosome dont make proteins. Thats not scientific.. ribsomes

are the site of protein synthesis

Describe two ways in which the structure of the mitochondria membrane is related to teh function of a mitochondrian

• highly permable to allow movement of molecules

• it is the site of ATP synthesis 

• contains electron carriers

mitochondria organelles functions and mitochondria itself

mitochondria is the site of aerobic respiration
cristae- foldings formed by extensions of inner membrane of mitochondria, has increased SA where resp processes occur.

double membrane- outer controls flow of materials in/out
matrix- site of krebs cycle, contains enzymes needed for aerobic respiration

Chloroplast structures in depth

• has compartmentalized sections to separate reactions of photosynthesis and maximize light absorption

• granum contains chlorophyll pigments required for process of photosynthesis

• large surface area formed by thylakoid stacks maximises space for enzymes and proteins required for photosynthesis

• internal membranes form thylakoid sacs, which stack to make granum

• lamella connect the thylakoid stacks, which allows for greater efficancy of photosynthesis

golgi apppartus function

• forms lyosomes

• transpors, modifies lipids

• secretes carbs

• adds non protein (carbs) to form glycoprotein

lyosome function

• digests worn out organelles

• breaks down dead cell - autolysis

• release tehir enzymes outside of cell (exocytosis)) in order to break down other cells

• digests material that have been ingested by the cell

Endoplasmic Reticulum description

system of sheet like membranes throughout cytoplasm.

the two types of endoplasmic reticulum and their descriptions, and functions

1. ROUGH er- ribosomes at surface

• processing of proteins for transport to the golgi apparatus 

SMOOTH er - no ribosomes

• stores and syntehsizes lipids

ALSO they both provide a structural skeleton to maintain cellular shape, provide a large SA for chemical reactions, provide a pathway for the transportation of materials thru cell

Rough ER and smooth draw it

rough smooth has the little tubes

All cells have an what?

Internal structure aka ULTRA STRUCTURE

Cell Vacuole (plants) description

contains cell sap made of weak solution of sugar and salts. has a surrounding membrane called a tonoplast.

Cell Wall description

Rigid structure that surrounds cells in plants and fungi.

Cell wall function

supports cell, prevents them from changing shape

Microvilli description

Finger like projections of epithililal cells. NOT present in all cells

Microvilli….

increases surface area for absorption in order to increase the rate of exchange of substances

Cilia

Hair like projections made from microtubules

Allows the movement of substances over cell surface

Flagella

in specialized cells - provides cell movement

Cytoskeleton location

The cytoskeleton is located in the cytoplasm of eukaryotic cells, extending from the nucleus to the cell membrane

2 types of ribosomes and describe

1. 80S type… eukaryotic cells

2. 70S… prokaryotic, smaller

Cytoskeleton is made of up

2 main types of protein fibers -

1. micro filament

2. microtubules

Micro filaments

solid strands that are mostly made of the globular protein ACTIN.

Microfilaments form the dynamic cytoskeleton, which gives structural support to cells and links the interior of the cell with the surroundings to convey information about the external environment.

Microfilaments provide cell motility. e.g., Filopodia, Lamellipodia.

During mitosis, intracellular organelles are transported by motor proteins to the daughter cells along actin cables.

In muscle cells, actin filaments are aligned and myosin proteins generate forces on the filaments to support muscle contraction.

MICROTUBULES

HOLLOW strands made of mostly the protein tubulin

• Microtubules determine the cell structure.

• Microtubules form the spindle apparatus to divide the chromosome directly during cell division (mitosis).

• Microtubules provide transport mechanism for vesicles containing essential materials to the rest of the cell.

• They form a rigid internal core that is used by microtubule-associated motor proteins (MAPs) such as Kinesin and Dyenin to generate force and movement in motile structures such as cilia and flagella.

chloroplast description. and function

Uses Light energy to produce sugars for photosynthesis

IMPORTANCE of cytoskeleton

• strengthing and support

• intercellular movement

• cell movement

Importance of cytoskeleton - strengthing and support

• provides cell with mechanical strength that forms sort of a scaffolding that helps to maintain the shape of the cell)

• supports organelles - keeps them in psoitojn

Importance of cytoskeleton - intercellular movement + example

• aids in transport within cell by forming tracks where organelles can move along

• examples include movements of chromosomes to opposite ends of cell during cell division.

Importance of cytoskeleton - cellular movement

• enables for cell movement via cilia and flagella

an stack of thylakoids aka

an granum

draw new organelles

plasma mebrane functions

• regulates movement of substances in out of cell

• receptor molecules on it allow it to respond to chemicals like horomones

golgi appartus description

similar structure to smooth er but more compact

has vessicles

vessicles are

flattened stacks of membranes with rounded structures

Golgi Vesicle

• small fluid filled sac at cytoplasm

• surrounded by a membrane

• made by golgi appartus

golgi vesicle func

• stores lipids and proteins made by golgi app and transports them out of cell by cell surface membrane

How does the rough endoplasmic reticulum (RER) contribute to protein formation?

RER has ribosomes attached; it folds and processes proteins after translation and transports them to the Golgi apparatus.

Which organelle is responsible for producing vesicles that transport proteins and lipids?

The Golgi apparatus – it packages modified proteins and lipids into secretory vesicles.

How are proteins and lipids secreted from the cell?

Vesicles fuse with the plasma membrane

all cellular organisms havew

ribosomes

How do lysosomes contribute to specialised cell function?

Lysosomes contain hydrolytic enzymes for breaking down waste, pathogens, or worn-out organelles – especially important in phagocytes like macrophages.

w is an amino acid in the cytoplasm secreted as a protein? ***

1. Nucleus

The process begins in the cell's nucleus, which houses the organism's DNA, the blueprint for all proteins. 

• Transcription: An enzyme called RNA polymerase creates a copy of a specific gene from the DNA. This copy is a messenger RNA (mRNA) molecule.

• mRNA processing: Before it leaves the nucleus, the newly created mRNA is modified. Non-coding regions called introns are removed, and the remaining protein-coding regions, or exons, are spliced together.

• Exit: The mature mRNA molecule then exits the nucleus through a nuclear pore and travels into the cytoplasm. 

2. Ribosomes

These are the cell's protein-building machinery. Ribosomes can be found freely floating in the cytoplasm or attached to the rough endoplasmic reticulum (RER). 

• Translation: In the cytoplasm, the ribosome binds to the mRNA molecule and reads the genetic code in three-nucleotide units called codons.

• tRNA delivery: Transfer RNA (tRNA) molecules carry specific amino acids that match the mRNA codons. The ribosome links these amino acids together in the correct sequence to form a polypeptide chain.

• Protein destination: If the protein is for use within the cell's cytoplasm, it is synthesized by free-floating ribosomes. If the protein is destined for secretion, another organelle, or insertion into a membrane, the ribosome carrying the mRNA attaches to the RER. 

3. Rough Endoplasmic Reticulum (RER)

The RER is a network of membranes connected to the outer nuclear membrane and studded with ribosomes, which give it a "rough" appearance. 

• Insertion: As a ribosome on the RER synthesizes a protein destined for export, the new polypeptide chain is threaded into the RER's internal space, known as the lumen.

• Folding and modification: Inside the RER, the polypeptide begins to fold into its correct three-dimensional shape. This process is assisted by chaperone proteins. Other modifications, such as the addition of carbohydrate groups (glycosylation), can also occur here.

• Vesicle transport: Once the protein is properly folded, it is packaged into a transport vesicle, a small, membrane-bound sac that buds off from the RER. 

4. Golgi Apparatus

The Golgi apparatus, or Golgi complex, is a stack of flattened, membrane-bound sacs called cisternae. 

• Receiving: Transport vesicles from the RER fuse with the receiving (cis) face of the Golgi, releasing the proteins inside.

• Further modification: As proteins move through the Golgi, they are further modified, sorted, and tagged with molecular "shipping labels" that determine their final destination.

• Packaging and export: At the opposite (trans) face, the finished proteins are packaged into new vesicles. Some vesicles transport the protein to other organelles, while others move to the cell membrane for secretion via exocytosis. 

5. Mitochondria

While not directly involved in protein synthesis, the mitochondria supply the energy necessary for this complex, multi-step process. 

Smooth Er

storage of carbs and lipids

function of chloroplast

Uses light to produce sugars for photosynthesis

how is a plant cell adapted for photosynthesis

Chloroplast - absorbs light

Vacuole - pushes chloroplast to edge of the cell

Cell wall - thin and permeable cell wall absorbs the CO2 needed for photosyntehsis

identify- chloroplast parts

identify- mitochondrian (also… the cristae is the what

the cristae is the extensions of the inner membrane that have been folded. 

when there are metabollically active cells, not only does the number of ___ increase, but thenumber of ___ increases as well bc..

the number of mitochondria increase, as does the number of cristae bc cristae is where the respiratory processes occur due to its increased SA

Mucus is a

glycoprotein

Organelles involved in protein production

1- nucleosus manufacture ribosomes for protein synthesis

2- nucleus manufacture mRNA (needed by ribosomes to make proteins)

3- ribosomes in RER to make protein

4- RER processed proteins sent to vesicles

5- GOLGI APP modified proteins and sends them in vesicles fuse with plasma membrane for EXCYTOSIS

Be able to identify GOBLET cells

structures only in animal cells

Centrioles and Microvilli

Plasmodesmata

Plasmodesmata are tiny cytoplasmic bridges that connect adjacent plant cells, enabling the direct exchange of substances such as ions, sugars, hormones, and signaling molecules.

Plants can control the size (permeability) of plasmodesmata:

• Open wider to allow more movement during growth.

• Narrow or close during stress or infection to prevent the spread of pathogens or toxins.

Lamelle

Forms the grana

Types:

• Granal lamellae: stacked membranes that form the grana (where light-dependent reactions happen).

• Stromal lamellae (intergranal lamellae): unstacked membranes that connect the grana.

specialised cell

A cell with particular adaptions in order to carry out its specific function.

Prokary cell wall is made of what

Murein 

Thykaloids site of

Light dependent stage

Stroma site of

Calvin Cycle

DRAW DETAILED ORGANELLES

Centrioles

Centrioles are cylindrical structures composed of nine sets of microtubule triplets arranged in a characteristic arrangement. They are found in most eukaryotic cells, typically as a pair known as a centrosome, located near the nucleus.

Centrioles are key cellular structures that play a central role in organizing microtubules and facilitating cell division, as well as forming basal bodies for cilia and flagella.n

Microtubules

Found in all ekatyoktic

MAKES UP THE CYTOSKELETON OF CELL

the little dots in a cell pic

B is lysosomes. A is nuclear envelope

what is magnification?

how many times larger an image appears compared to the actual size of the object

What is resolution?

the minimum ability to be able to see different objects as two separate enitities.

on the stage micrometer 1 division

0.01 mm

2 main microscopes

optical microscope and electron microscope

electron microscopes types

• transmission electron microscope (2d)

• scanning electron (3d)

in light microscopes, why can’t we see the organelles?

max resolution and mag

200nm and mag is 1500x

how electron microscope works - TEM

• coats spectrum in resin to form solid block

• thin slices are made, and stained with heavy metals

• electrons pass thru the thin slice of material and are absorbed by the heavier stained metals. As they pass, they are photographed by electromagnets on the film.

TEM captures . SEM captures _.

tem organelles. sem is whole cells, tissues, organisms

scanning is about

how it’s reflected

steps of how scanning electron microscope works

• specium coated w/ thin layer of metal (like gold, tungsten, silver) to improve conductivity

• electrons are reflected from the surface of specium, producing a 3D shape

limits of electron microscope

complex, expensive, can’t look at living cells, ARTEFACTS can be made from preperation, black and white

how to observe the cells in a prepared slide using light microscope

• clip slide onto stage

• select lowest powered objective lens

• use course knob to bring stage just below objective lens

• look down the eyepiece and use coarse knob to move stage down till image is roughly focused

• adjust focus with fine knob till image is clear

• if greater magnification is required refocus using a higher powered objective lens

artefact

things that shouldn’t be there bc of staining in electron microscope

Temporary mount

where the specimen is suspended in a drop liquid on the slide. the microscopy which Enchances colour of the spec

Why is the resolution of Electron microscope higher than the resolution of a image using optical

electrons have much shorter wavelengths than photons (light particles), allowing them to resolve smaller details

how to measure for size of a structure (real)

1. measure image in mm and divide by mag

2. convert image to micrometres

3. divide image size by length of scale

4. multiply real length of scale bar

Why is it important for a leaf tissue to be very thin when observed

Thiness allows for light to pass thru specimun

What are the measurement conversions needed for magnification?

describe the steps to preparing a microscope slide using a temporary mount?

- begin by pipetting a small drop of water onto the centre of the slide.
2
- you will then need to place a thin section of your specimen on top of the water drop through using tweezers.
3
- add a drop of stain. stains are used to highlight objects in a cell.
4
-add a cover slip.
-do this by standing the slide upright on the slide, next to the water droplet.
-carefully tilt and lower so specimen is covered.
-ensure no air bubbles are seen. they'll obstruct view of specimen.

describe how you could make a temporary mount of a piece of plant tissue to observe the position of starch grains in the cells when using an optical light

1. add a drop of water to glass slide

2. obtain thin slice of plant tissue and place slice on drop pf water

3. stain with iodine in potassium odiine

4. lower cover slip using mounted needle

Cell and cellular structures are often . This makes it difficult to visualize components while using a light microscope. Staining techniques use coloured dyes to . Using multiple diff dyes to stain diff parts of specimen is known as ____ staining. For example, _____ is a dye which stains cell red.

Transparent, distinguish organelles, differiential, phloroglucinol

Prokaryotic Cell

organism without a membrane boudn organelles

tyoes of prokary

bacteria and archaea

ex of bacteria

e coli, chloera, cyanobacteria

List of prok structures

cell wall, capusle, cell membrane, dna, plasmids, cytoplasm, ribosome, mesosome, pilli,

How does cell division occur

Binary Fission, no spindle

Pilli

For attachment to other cells, involved in sexual rep

How do cells divide in eurkaryote

Mitosis or MEIosis and involves a spindle to seperate chromosomes

description of structures… dna

aka the nucleoid/genophore

free in cytoplasm