Cell structure and microscopes

what are Eukaryotic Cells

Cells that have a nucleus and membrane-bound organelles.

Prokaryotic Cells

Cells that lack a nucleus and are smaller/simpler, such as bacteria.

Organelles in Prokaryotic Cells

Cell membrane, cell wall, cytoplasm, ribosomes, loop of DNA, plasmids, flagella, capsule.

Function of Plasmids

Small loops of extra DNA that can carry genes for antibiotic resistance and other survival traits.

Function of Flagella

Allow movement, enabling bacteria to reach nutrients or escape harmful conditions.

Function of the Nucleus

Controls cell activities and stores DNA.

Function of Mitochondria

Site of aerobic respiration, producing ATP (energy).

Function of Ribosomes

Assemble proteins from amino acids during protein synthesis.

Function of Cytoplasm

Where chemical reactions occur, aided by enzymes.

Function of Cell Membrane

Controls what enters and leaves the cell.

Additional Organelles in Plant Cells

Cell wall, chloroplasts, vacuole.

Function of Cell Walls in Plants

Provide structural support and shape maintenance.

Contents of Vacuole

Cell sap, which helps maintain rigidity.

Function of Chloroplasts

Carry out photosynthesis, converting light energy into glucose.

Purpose of Chlorophyll in Chloroplasts

To absorb light for photosynthesis.

Formula for Magnification

Magnification = Image Size ÷ Actual Size.

Calculating Total Magnification

Multiply the eyepiece lens magnification by the objective lens magnification.

Difference Between Magnification and Resolution

Magnification increases the size of an image, while resolution affects clarity.

Differences Between Light and Electron Microscopes

Light microscopes have lower resolution and are used for living cells; electron microscopes have higher resolution and reveal ultrastructure like ribosomes.

Detail Provided by Electron Microscopes

They use electron beams instead of light, providing higher resolution.

Steps to Prepare a Microscope Slide

Place specimen on slide, add stain for contrast, lower cover slip carefully, adjust focus on the microscope.

Purpose of Staining Specimens

To enhance contrast, making organelles more visible.

Iodine use

A stain commonly used for plant cells.

Methylene blue

A stain commonly used for animal cells.

Sperm cell adaptation

Tail for movement, mitochondria for energy, enzymes to break into egg.

Nerve cell long axon function

to transmit signals quickly over long distances.

Root hair cell

Absorbs water efficiently due to its large surface area allowing better water/mineral uptake.

Xylem vessels

Transport water through the plant and provide structural support.

Phloem cells

Transport nutrients by moving sugars around the plant using companion cells for energy.

Loop of DNA in prokaryotic cells

Carries genetic information, controlling cell activities like a nucleus would in eukaryotic cells.

what are Plasmids

Small loops of extra DNA carrying genes for antibiotic resistance and other survival traits.

Cell membrane in bacteria

Controls substance movement into and out of the cell, similar to eukaryotic cells.

Cell wall in bacteria

Provides support and protection, preventing the cell from bursting in different environments.

Capsule in bacteria function

Protects bacteria from drying out, immune attack, and helps stick to surfaces.

Flagella in bacteria

Allows movement, helping bacteria swim toward nutrients or away from harm.

Ribosomes in prokaryotic cells

protein synthesis

Red blood cell adaptation

No nucleus for more space for haemoglobin and a biconcave shape to maximize oxygen absorption, due to higher surface area

Ciliated epithelial cells function

Have tiny hairs (cilia) that move mucus containing dust and bacteria out of the airways.

Muscle cells mitochondria

Contain many mitochondria to provide large amounts of ATP for muscle contraction.

Palisade cell function

Contains many chloroplasts, maximizing photosynthesis for food production.

Guard cells

Change shape to open or close the stomata, regulating water loss and CO2 intake.

Fat cells (adipocytes)

Store energy in the form of lipids, providing insulation and protection.

Neurons specialization

Have long axons to transmit electrical impulses over long distances.

Stem cells

Undifferentiated cells that can divide and become different types of cells.

Phloem cell nutrient transport

Has sieve plates for rapid sugar flow and companion cells providing energy.