BioE002- Fundamentals of Molecular Biology Chapter 1

Transcription

Process of copying a segment of DNA into RNA

Translation

Process of by which a cell makes proteins using the genetic information carried in messenger RNA (mRNA)

Origin of first cell

Appeared 3.8 billion years ago by enclosure of a self-replicating RNA in a phospholipid membrane.

Metabolism

Conversion of energy in food to energy available to run all processes, conversion of food to building blocks of proteins, lipids, nucleic acids, and proteins, elimination of metabolic waste

Glycolysis

Process that uses ATP as a primary energy source. C₆H₁₂O₆ (glucose) → 2C₃H₃O₃ (pyruvate). Generates 2 ATP

Photosynthesis

Process that uses ATP as a primary energy source. 6CO₂ + 6H₂O -(sun)→ C₆H₁₂O₆ (glucose) + 6O₂

Oxidative Metabolism

Process that uses ATP as a primary energy source. C₆H₁₂O₆ → 6CO₂ + 6H₂O Generates 36-38 ATP

Prokaryotic Cell

Cell with no nucleus found in single cell organisms (bacteria, archae). Surrounded by cell wall containing plasma membrane. No nucleus, DNA is in the nucleoid. Most of these organisms are small, simple creatures.

Eukaryotic Cell

Found in plant and animal cells. In both cells they are surrounded by plasma membrane and have nucleus. Plant cells have chloroplasts used in photosynthesis.

Lysosomes

Metabolizes waste

Animal Cell Only

Lysosomes, centrioles, flagella

Plant Cell only

Chloroplasts, central vacuole and tonoplast, cell wall, plasmodesmata

Prokaryote

No nucleus, around 1um diameter, no cytoplasmic organelles, single cellular DNA molecule

Eukaryote

present nucleus, 10-100um diameter, present cytoplsamic organelles, Multiple linear DNA molecules

Germ layer

Layer of cells that forms during embryonic development.

Endoderm

Innermost germ layer in early embryo. Codes for lungs, thyroid, pancreatic cells

Mesoderm

Middle germ layer in early embryo. Codes for cardiac, skeletal muscle, tubule, red blood, smooth muscle cells.

Ectoderm

Outermost germ layer in early embryo. Codes for epidermis, neuron, pigment cells.

Origin of mitochondria

Arose from internalization of aerobic bacteria by the archaeal ancestor to eukaryotes, after which they continued living symbiotically.

Animal Cell culture process

Tissue dispersed into suspension of individual cells → cells plated in culture dish in nutrient medium → cells in primary culture attach to dish and grow until culture dish surface is covered → cells can be removed from culture dish and replated at lower density to form secondary culture

Plant tissue culture process

tissue sample scraped from parent → sample placed in agar growth medium containing nutrients and auxins → samples develop into tiny plantlets → plantlets placed into compost

Fluorescent microscopes

Use fluorescent stains to produce an image and identify pathogens, find species, distinguish cells

Confocal microscopes

Use lasers to construct 3D images on computer, allowing examination of thick specimens

Excitation of fluorophore

Entails absorption of light energy of a certain wavelength, causing an electron to transition to a higher, excited energy state. Electron will return to ground state, resulting in emission of light at a longer wavelength

Multiphoton Microscopy

Useful for visualizing cells positioned deeper within living tissue

Centrifugation

Allows different subcellular components to be separated at certain speeds.

Density Gradients

Can be used to separate sub cellular components based on buoyant density independent of size and shape

Differential Centrifugation

Used in subcellular fractionation studies of archaea, bacteria, and eukaryotes

Adenine 5’-Triphosphate (ATP)

All cells use this as their primary energy source.

Cell Wall

Surrounds cell. Beneath this organelle, is the cell membrane

Prokaryote examples

Bacteria and Archae

Chloroplast

Organelles responsible for photosynthesis

Large Vacuole

AKA central vacuole. A sac-like organelle in plant cells that stores water, nutrients, and waste products

Endosymbiosis

One cell living inside another. Mitochondria arose from endocytosis (internalization) of
aerobic bacteria by the archaeal
ancestor to eukaryotes, after which
they continued living symbiotically. Like Russian nesting dolls.

Yeasts

Simplest eukaryotes

Eubacteria

Lactococus lactis

Mass of archaeans

Human blood cells in false color

Colonial single-celled green alga, Volvox aureus

Single Purkinje neuron of the celebrum

Plant cells are fixed firmly in vascular plants

Supported by rigid cellulose skeleton

Epithelial cells

Form the covering of all body surfaces, line body cavities and hollow organs, and are the major tissue in glands. They perform a variety of functions that include protection, secretion, absorption, excretion, filtration, diffusion, and sensory reception.

Fibroblasts

cells that create and maintain connective tissues, which support and connect organs and tissues. They also play a role in wound healing. 

Blood cells