Topic 1 - Cellular Biology

70s Ribosomes

Ribosomes that are smaller in size and freer in cytoplasm, used for protein synthesis.

80s Ribosomes

Larger ribosomes in eukaryotic cells that are made up of a smaller 30s subunit and a larger 50s subunit and are often associated with different cell organelles.

Active Transport

A process that allows the cell to take in substances even though there is a higher concentration in the cell; molecules enter a protein pump, and ATP is used.

Adult Stem Cells

The daughter cell of an embryonic stem cell, they have limited functions, and are multipotent.

Amphipathic

Substances that are both attracted and not attracted to water.

Anaphase

The stage in mitosis where the sister chromatids split into individual chromosomes, and each chromosome is pulled to an opposite pole by the centriole.

Apoptosis

A natural part of the cell cycle where cells that are no longer useful undergo cell suicide.

Artificial Insemination

When sperm collected from sperm banks is inserted into a woman's cervix by a doctor.

Asexual Reproduction

When an organism reproduces by making a copy of itself. Offspring are clones and there is not much genetic variation.

Axons

Parts of neuron that convey messages rapidly in an electrical form called a nerve impulse.

Bilayer

Composed of two molecules in which each molecule is arranged with its hydrophobic end directed inward toward the opposite side of the film and its hydrophilic end directed outward.

Binary Fission

A form of asexual reproduction where the parent cell divides into two genetically identical daughter cells.

Cancer

A deadly disease where DNA is accidentally changed in the cell cycle, which allows cancer cells to divide uncontrollably.

Carcinogens

Cancer causing chemicals

Cell

The smallest living unit of life.

Cell Membrane

The protective barrier around the cell.

Cell Replacement Therapy

The transplantation of stem cells to replace damaged cells.

Cell Specialization

The process in which a cell becomes specialized to perform a specific function.

Cell Theory

The theory that: The cell is the building block of life, all living organisms are composed of one or more cells, and all cells come from pre-existing cells.

Cell Wall

A rigid frame that provides the cell support, strength and protection. Only in plants (cellulose microfibrils ) and prokaryotic cells (peptidoglycan).

Centrioles

Organize microtubules during mitosis. Only in animals.

Channels

They have diameter and chemical properties that ensure that only one type of particle can pass through.

Functions of Life

Made of cells, respond to changes in the environment, can reproduce, exchanges energy and matter with the environment, has metabolism, maintains homeostasis, can grow.

Chlorophyll

The green pigment in plants that allows cells to absorb energy from the sun.

Chloroplast

Contains chlorophyll used for photosynthesis. Only in plants.

Cholesterol

Part lipid, part protein. Make phospholipids more tightly packed and regulate the fluidity and flexibility of the membrane.

Chromatid

Formed when the cell undergoes mitosis or meiosis, is one half of a chromosome.

Chromatin

Uncondensed genetic information that is contained inside the nucleus.

Chromosome

Formed by two identical chromatids and carries important genetic information.

Cillia

Hair-like organelles which moves materials around and prevents pathogens from invading the body.

Cisternae

Flattened membrane sacs.

Conjugation

A form of sexual reproduction where bacteria transfer genetic material by fusing together to form offspring.

Cyclins

Proteins that help to regulate the cell cycle

Cytokinesis

Where the cytoplasm divides, the plasma membrane pinches and constricts and the membrane fuses and seals with the addition of new membrane formed.

Cytoplasm

A jelly-like substance that surrounds the organelles.

Cytoskeleton

An internal network of fibres that helps to maintain the cell's shape.

Davson-Danielli Model

A model that suggests that the protein membrane looks like a sandwich, that proteins form distinct layers and contains phospholipids

Falsification of Davson-Danielli Model

Fluorescent antibody tagging of membrane proteins showed they were *mobile* and not fixed in place, Freeze fracturing was used to split open the membrane and revealed irregular rough surfaces within the membrane

Dermis

The inner layer of the skin which is composed of connective and muscular tissues.

Diameter of Field View Equation

Diameter of high power/diameter of low power = magnification of low power/magnification of high power

Drawing of a Eukaryotic Cell

When drawing this cell, please include cell membrane, nucleus, rough endoplasmic reticulum with 80s ribosomes, golgi apparatus, mitochondria, and free 80s ribosomes. If necessary, include a chloroplast with thylakoids and a large vacuole.

Drawing of a Prokaryotic Cell

When drawing this cell, please include 70s ribosomes, cell wall, plasma membrane, cytoplasm, nucleoid, pili, and flagella. Use e.coli as the reference cell type.

Ectoderm

Cells that give rise to cells that form the skin and nervous system.

Electron Micrograph

A graphic representation of an image of an object under an electron microscope.

Embryonic Stem Cells

The main type of stem cells containing embryos, these cells can specialize to perform any function, and are pluripotent.

Endocrine Gland Cells

Cells that are involved in the control of appetite, digestive processes, and metabolism and an important source of hormones.

Endocytosis

A process in which a vesicle is formed on the inside of the plasma membrane and allows water, solutes, and larger molecules that cannot pass through the cell membrane to enter the cell.

Endoderm

Cells that give rise to cells that form the gastrointestinal and respiratory tract.

Endosymbiotic Theory

The relationship in which one cell lives inside of the other and in some cases, one cell cannot live without the other.

Epidermal Tissue

An outer coating that is involved in water entering roots and gases entering and leaving leaf.

Epidermis

The outer layer of the skin which is composed of epithelial tissues.

Epithelial Tissue

The tissue that lines body cavities and outer surface of body, and forms a protective barrier.

Eukaryotic Cells

Cells that contain a nucleus to hold DNA and membrane-bound organelles as well as 80s ribosomes.

Evidence for Endosymbiotic Theory

Ultrastructure of organelles such as mitochondria and chloroplast resembles some bacterial structure, they have DNA, and can move freely around the cell.

Exocrine Gland Cells

Cells that secrete products into the digestive tract like bile and pancreatic juice that also help secrete digestive enzymes which break down food in the small intestine.

Exocytosis

A process in which a vesicle fuses with the plasma membrane and releases contents such as waste products and unwanted material out of the cell.

External Fertilization

When gametes meet outside of an adult to begin forming a new organism.

Extracellular

Components of the cell that are outside of the cells main body.

Facilitated Diffusion

Ions and other particles that cannot diffuse between phospholipids can pass in or out of cells if there are channels for them.

Flagella

A tail-like structure that acts as a propulsion for a cell which allows it to move.

Function of Proteins

Transport, anchorage, receptors, cell recognition, enzymatic activity, and intercellular joining.

Fungi Hyphae Cells

These cells differentiate from cell theory by being multinucleated and having continuous cytoplasm along the hyphae with no end cell wall or cell membrane.

G1 Phase

The stage in interphase where the cell produces new cells and proteins.

G2 Phase

The stage in interphase where the cell produces organelles and structures needed for cell division.

Gametes

Sperm and egg cells which have half as many chromosomes as a body cell.

Gene Therapy

The process of replacing absent or faulty genes with normal ones to treat diseases.

Genes

Things that make up your DNA which determine certain traits in organisms.

Giant Algae Cells

These cells differentiate from cell theory because they can grow up to 100 mm despite having only one nucleus.

Glycolipid

A sugar chain attached to a phospholipid.

Glycoprotein

A sugar chain attached to a membrane protein.

Golgi Apparatus

Modifies, sorts, and packages proteins from the endoplasmic reticulum for delivery.

Histone Proteins

Associated with DNA.

Homeostasis

The steady state that is maintained by an organism which is necessary for survival.

Hydrophilic

Substances that are attracted to water.

Hydrophobic

Substances that are not attracted to water.

Hypertonic

Where there is a net movement of water out of the cell which causes the cell to shrink and shrivel.

Hypotonic

Where there is a net movement of water in the cell which causes the cell to expand and rupture.

In-Vitro Fertilization

When sperm and eggs are collected in petri dishes where fertilization occurs and the developing embryo is injected into the womb of a female.

Integral Proteins

A protein that is hydrophobic on part of its surface and embedded in hydrocarbon chains in the centre of the membrane, many are transmembrane (extend across the cell membrane).

Internal Fertilization

When gametes meet inside of a female to begin forming a new organism.

Interphase

This takes place when the cell is preparing for cell division.

Isotonic

Where the net movement of water in and out of the cell is the same and the cell stays the same size.

Karyotype

The preparation of the complete set of an individual's chromosomes.

Liposome

A bilayer of phospholipids.

Lymphoid Cells

Any cell types responsible for the immune system.

Magnification Equation

Magnification = size of image/actual size of specimen.

Malignant

Harmful and cancerous tumours that have the potential to spread throughout the body.

Meiosis

Occurs only through sexual reproduction when one cell divides twice to form four daughter cells containing half the chromosomes of the parent cell.

Meristematic Tissue

This unspecialized plant tissue can divide by mitosis.

Mesoderm

Cells that give rise to cells that form bone, cartilage, connective tissue, and the majority of the circulatory system.

Metabolism

Chemical reactions in a cell.

Metaphase

The stage in mitosis where the chromosomes move to the middle and the mitotic spindles from the centrioles attach to the centromere.

Metastatic

Tumours that have already travelled and grown in other areas of the body.

Micelle

A single layer of phospholipids.

Microtubules

These move chromosomes during cell division.

Mitochondria

The powerhouse of the cell, produces ATP, made up of cristae (folds in the inner membrane of mitochondria).

Mitosis

This is when a parent cell is dividing to form two daughter cells.

Mitotic Index

Number of cells in mitosis/total number of cells * 100

Multipotent Cells

These cells can differentiate into committed precursors of each cell type, their ability to differentiate into cell types is limited to what type of multipotent cells they are.

Mutagens

Agents that cause gene mutations