chapters 4 5 6 lecture

These flashcards cover key concepts from cell biology and microscopy, including the structure and function of cells, various types of microscopes, and the role of enzymes in cellular processes.

What did Robert Hooke discover through his microscope in 1665?

He discovered cells and referred to them as 'little rooms'.

What is the primary purpose of a light microscope?

To magnify specimens using visible light, allowing objects to be seen up to 1,000 times their actual size.

Define magnification in microscopy.

Magnification is the increase in an object's image size compared with its actual size.

What does resolution refer to in microscopy?

Resolution is a measure of the clarity of an image, or the ability to distinguish between small structures.

What is the cell theory?

The cell theory states that all living things are composed of cells, and all cells arise from pre-existing cells.

What is the difference between light microscopes and electron microscopes?

Light microscopes use visible light to magnify specimens, while electron microscopes use a beam of electrons, allowing for higher resolution and magnification.

What are the main functions of the endoplasmic reticulum?

The endoplasmic reticulum is involved in the synthesis of proteins and lipids, as well as detoxification processes.

What are lysosomes?

Lysosomes are membrane-enclosed sacs of digestive enzymes that break down macromolecules and recycle cellular components.

What is the role of mitochondria in a cell?

Mitochondria are the organelles that carry out cellular respiration, converting chemical energy from food into ATP.

What is the structural component of a plasma membrane?

The plasma membrane is composed of a phospholipid bilayer with embedded proteins that regulate the movement of substances in and out of the cell.

What is osmosis?

Osmosis is the diffusion of water across a selectively permeable membrane.

Differentiate between isotonic, hypotonic, and hypertonic solutions in relation to animal cells.

Isotonic solutions have equal solute concentration; hypotonic solutions cause cells to swell and possibly burst; hypertonic solutions cause cells to shrink and die.

What are cellular junctions and name the three types found in animal tissues.

Cellular junctions are specialized connections between adjacent cells; the three types are tight junctions, anchoring junctions, and gap junctions.

What is feedback inhibition in enzymatic reactions?

Feedback inhibition occurs when the product of a reaction acts as an inhibitor for one of the enzymes involved in its production.

What are the two basic forms of energy relevant to cellular processes?

Kinetic energy (energy of motion) and potential energy (energy stored due to position or structure).

What is the importance of ATP in cellular metabolism?

ATP provides energy for various cellular processes by transferring its phosphate groups to other molecules.

Explain the difference between competitive and noncompetitive inhibitors.

Competitive inhibitors block substrates from binding to the active site, while noncompetitive inhibitors bind to another site and change the shape of the enzyme.

What does the term 'metabolism' encompass?

Metabolism encompasses all chemical reactions occurring within an organism.

What is the fluid mosaic model?

The fluid mosaic model describes the structure of cell membranes as a patchwork of various proteins embedded in a phospholipid bilayer.