Cell Biology

Eukaryotes

A type of cell found in plants and animals with a nucleus.

Prokaryotes

A type of cell found in bacteria that does not contain a nucleus.

Cell Size

The microscopic size of cells are typically measured in micrometers (μm) or nanometers (nm).

Micrometre

It is used to express the size of microscopic structures such as cells, cellular organelles, and microorganisms (symbol - μm)

Nanometre

It is used to used to express very small lengths, particularly at the nanoscale (symbol - nm)

Order of Magnitude

It is the approximate size or scale of a biological entity or process, typically expressed as a power of 10.

Standard Form

A way of expressing number sizes as a power of ten.

Prefixes

Terms before units of measurement to indicate multiples or fractions of the unit.

Animal Cells

Cells found in animals that have specific subcellular structures such as the nucleus, cytoplasm, mitochondria, cell membrane, and ribosomes.

Plant Cells

Cells found in plants that have additional subcellular structures such as the cell wall, chloroplasts, and permanent vacuole.

Nucleus

 A large organelle in eukaryotic organisms that protects the majority of the DNA within each cell

Cytoplasm

Responsible for holding the components of the cell and protecting them from damage

Mitochondria

Is where the aerobic respiration reaction occurs and is considered the energy factory of the cell

Cell Membrane

Regulates the transport of materials entering and exiting the cell

Ribosome

 It is where protein synthesis occurs and is found on a structure called “rough endoplasmic reticulum”

Cell Wall

A wall made of cellulose to strengthen the cell

Chloroplast

Produce energy through photosynthesis and oxygen-release processes, which sustain plant growth and crop yield

Permanent Vacuole

Found within the cytoplasm and functions as storage and transport, intracellular environmental stability, and response to injury

Cell Specialisation

The process by which cells differentiate to form specific cells with specific functions.

Sperm Cell

Specialised to carry male’s DNA for fertilisation and reproduction

Nerve Cells

Specialised to transmit the body's electrical impulses from one place to another

Muscle Cells

Specialised for contraction and allowing movement

Root Hair Cells

Specialised to take up (absorb) water and mineral ions

Xylem Cells

Specialised to transport water up the stem of a plant and into the leaves

Phloem Cells

Specialised to transport food products to parts of the plant where they are needed.

Sieve tubes

Specialised for transport and have no nuclei.

Companion cells

Are attached to each sieve tube provide this energy

Cell Differentiation

The process by which a less specific cell develops and matures to become more distinct in form and function.

Microscopy

The use of microscopes to view extremely small structures or objects.

Light Microscopy

A technique that uses visible light to magnify and view specimens.

Electron Microscopy

A technique that uses electron beams to magnify and view specimens with higher resolution than light microscopy.

Transmission Electron Microscope (TEM)

Used to view thin specimens (tissue sections, molecules, etc.) through which electrons can pass, generating a projection image

Scanning Electron Microscope (SEM)

Used to examine and analyse micro- and nanoparticle imaging characterization of solid objects

Magnification of Microscope Formula

magnification of eyepiece lens x magnification of objective lens = magnification of microscope

Magnification of an Image Formula

size of an image / real size of object = magnification

Microorganisms

Microscopic organisms such as bacteria, fungi, archaea, or protists.

Culturing Microorganisms

The method of growing microorganisms in a controlled laboratory environment.

Nutrient Broth Solution

A liquid medium used for the cultivation of various microorganisms.

Agar Gel Plate

A solid medium used to grow bacteria and fungi in a microbiology laboratory.

Aseptic Technique

A method used to prevent contamination during the handling and culturing of microorganisms.

Sterilization

The process of eliminating unwanted organisms from a culture medium or laboratory environment to prevent contamination.

Inoculating loops

Tools used to transfer microorganisms to culture media, which must be sterilized to prevent contamination.

Secure lid

The use of adhesive tape to seal the Petri dish, preventing air contamination and protecting the plate from external factors.

Upside-down storage

Storing Petri dishes upside down to prevent condensation from disrupting the growth process on the agar surface.

Incubation temperature

The recommended temperature of 25°C for microorganism growth in school laboratories.

Mean Division Time

The average time it takes for one bacterial cell to divide once.

Bacterial Population Growth Formula

bacteria at beginning x 2 ⁿᵘᵐᵇᵉʳ ᵒᶠ ᵈⁱᵛⁱˢⁱᵒⁿˢ = bacteria at end

Chromosomes

Threadlike structures in the nucleus that carry genetic information from cell to cell.

DNA Molecule

The molecule that carries genetic information for the development and functioning of an organism.

Genes

Segments of DNA that carry instructions for building and maintaining an organism.

Sex Chromosomes

A type of chromosome that identifies the sex of an individual

Cell Cycle

The series of steps a cell must undergo to divide, including interphase, mitosis, and cytokinesis.

Mitosis

The process of cell division where each daughter cell receives a complete set of chromosomes

Stem Cells

Cells with the potential to develop into numerous types of cells in the body

Embryonic Stem Cells

Stem cells obtained from early-stage embryos that can differentiate into almost any cell in the body

Adult Stem Cells

Stem cells found in various parts of the body that can differentiate into specific types of cells

Meristems of Plants

The centre of active mitotic cell division where plant growth occurs

Therapeutic Cloning

Producing an embryo with the same genes as the patient to obtain embryonic stem cells for medical treatment.

Diffusion

The movement of particles from an area of higher concentration to an area of lower concentration.

Concentration Gradient

The difference in concentration between two areas that affects the rate of diffusion.

Surface Area to Volume Ratio

Refers to how much surface area an object or collection of objects has per unit volume

Osmosis

The diffusion of water from a dilute solution to a concentrated solution through a partially permeable membrane.

Endosmosis

Refers to when a substance is placed in a hypotonic solution, the solvent molecules move inside the cell and the cell becomes turgid or undergoes deplasmolysis

Exosmosis

Refers to when a substance is placed in a hypertonic solution, the solvent molecules move outside the cell and the cell becomes flaccid or undergoes plasmolysis

The Rate of Water Uptake Formula

change in mass x 60 minutes/period of time measured in minutes

Active Transport

A process that moves molecules or substances against a concentration gradient and requires energy from respiration.