Using Food and Controlling Growth (OCR)

Aerobic Respiration

Aerobic Respiration

Occurs with oxygen and releases more energy but more slowly, mostly occurs in eukaryotic organisms.

Aerobic Respiration Input

Glucose (C6H12O6) and Oxygen (O2)

Aerobic Respiration Output

Carbon dioxide (CO2) and Water (H2O)

Anaerobic Respiration

Occurs without oxygen and releases less energy but more quickly and is used by some organisms as a primary energy source or when oxygen is limited.

Anaerobic Respiration Input

Glucose (C6H12O6)

Anaerobic Respiration Output

Lactic acid (C3H6O3) in lactic acid fermentation, Ethanol (C2H5OH) and carbon dioxide (CO2) in alcoholic fermentation

Cellular Respiration

An exothermic process where the breaking of carbon-hydrogen covalent bonds within sugars releases energy into the environment.

Rate of Oxygen Consumption (v) Formula

v = - Δ[O2] / Δt

Rate of ATP Production (v_ATP)

v_ATP = v * (36-38 ATP molecules) / (6 O2 molecules)

Electron Microscopy

A powerful tool that allows scientists to visualize objects much smaller than what can be seen with a traditional light microscope.

Transmission Electron Microscopy (TEM)

Transmits electrons through the sample, creating a high-resolution black and white image.

Scanning Electron Microscopy (SEM)

Scans a focused electron beam across the surface of the sample, generating a three-dimensional image.

Estimations

Valuable tools in cell biology, especially when dealing with immense numbers or sizes.

Standard Form

(or scientific notation), allows us to efficiently write very large or small numbers used in cellular dimensions.

Cell Cycle

A sequence of events where a single cell grows, replicates its DNA, and divides to form two daughter cells.

Interphase

The longest stage which occupies about 90% of the cell cycle. It is when cells undergoes growth, replication of DNA, and preparation for mitosis.

Mitosis

A phase where the cell divides into two daughter cells.

Prophase

It is when chromosomes condense and become visible.

Prometaphase

It is when spindle fibers, formed from microtubules, start to attach to chromosomes.

Metaphase

It is when chromosomes align at the center of the cell (metaphase plate) for separation.

Anaphase

It is when sister chromatids (copies of each chromosome) are pulled apart by spindle fibers towards opposite poles of the cell.

Telophase

It is when nuclear envelopes reform around the separated chromosomes at each pole; the chromosomes decondense.

Cancer

A non-communicable disease in humans caused by changes in a person’s DNA.

Mutations

(in genes), that regulate cell growth and division are a hallmark of cancer.

Epigenetics

Modifications that influence gene expression without altering the DNA sequence itself.

Meiosis

A specialized cell division process that ensures the creation of gametes (sex cells) with half the number of chromosomes compared to the parent cell.

Gametes

A different type of cell division produces by meiosis which contain half the number of chromosomes found in body cells (one chromosome from each pair).

Meiosis I

The critical stage where the chromosome number is reduced by half.

Meiosis II

Resembles a typical mitosis, but operates on the daughter cells produced from meiosis I, which already have half the chromosome number.

Stem Cells

Unspecialized cells with the remarkable potential to develop into various specialized cell types. 

2 Main Types of Animal Stem Cells

Embryonic Stem Cells (ESCs) and Adult Stem Cells

Embryonic Stem Cells (ESCs)

(pluripotent stem cells) meaning they have the extraordinary ability to differentiate into any cell type within an organism.

Adult Stem Cells

(multipotent stem cells) meaning they can differentiate into a limited number of cell types specific to their tissue of origin.

Meristems

Regions of rapid cell division in plants, responsible for their growth and development.

2 Main Types of Meristems

Apical and Lateral Meristems

Apical Meristems

Responsible for primary growth, making the plant taller or longer that is located at the tips of roots and shoots.

Lateral Meristems

Contribute to secondary growth, increasing the plant's thickness that is found in the plant body.

Cell Differentiation

The transformation of unspecialized stem cells into a diverse array of specialized cells, each with a unique structure and function. 

Plant Hormones

Helps plants respond to their environment in different ways.

Auxins

One of the most well-studied plant hormones, plays a crucial role in many of these processes.

Phototropism

The bending of plant shoots towards a light source.

Gravitropism

The growth of roots downward and shoots upward in response to gravity.

Gibberellins (GA)

Involved in breaking seed dormancy (germination) in response to water, and bolting (production of flowers in an attempt to reproduce before death) in response to cold or lack of water.

Stem Elongation

Promoted by stimulating cell division and elongation in internodes (the stem regions between nodes).

Parthenocarpy

Fruit development without fertilization

Ethylene (C2H4)

Involved in the ripening of fruit and dropping of leaves.

Benefits of Stem Cell Therapy

Treatment of Incurable Diseases, Improved Organ Transplants, and Drug Discovery and Testing

Risks of Stem Cell Therapy

Tumor Formation, Immune Rejection, and Ethical Concerns

Ethical Issues of Stem Cell Therapy

Embryonic Stem Cells, Informed Consent, and Fairness and Access