Bio chapter 4

Describe the importance of microscopes in understanding cell structure and function

Its used to study cytology, the study of cell structure. mixture of biochemistry used to study the chemical process ( metabolism of cells

Compare the structures and functions of the cytoskeleton and its components including: microfilaments, intermediate filaments, and microtubules

The cytoskeleton: supports the plasma membrane and gives cell an overall shape, aids and positioning of organelles, provides tracks for transports and vesicles, allows the cell to move Microfilaments: combined in a structure that resembles a double helix. involved in cell shape, cell movement, made of actin filaments ( proteins) Microtubules: thickest tube \, shape and support the cell, form tracks for organelle movement, made of tubulin protein Intermediate filaments: shape and support cell and organelles, often permanent fixtures, made up of diff types of protein including types of keratin, half the size of microtubules

The structures and functions of tight junctions, anchoring junctions, and gap junctions

Tight Junctions- the plasma membranes of neighboring cells are tightly pressed against each other and knit together by proteins. They prevent leaking of fluid across a layer of cells. Anchoring Junctions- Function like rivets by fastening cells together into strong sheets. Common in tissues subject to stretching or mechanical stress, such as skin and heart muscle. Gap junctions- Communicating junctions. Channels that allow small molecules to flow through protein-lined pores between cells. Common in embryos where communication between cells is essential for development.

describe the two parts of a cell theory

all living things are composed of cells and all cells come from other cells

Explain why the surface area to volume ratio limits cell size

as a cell grows, its surface area/ volume ration decreases. At some point of the cells growth, the surface area/ volume ratio becomes so small that the surface area is too small to supply raw materials to its volume. here the cell cannot get any bigger

Describe the evidence that suggests Chloroplast evolved by endosymbiosis.

chloroplast are like tiny green factories within plant cells that help convert energy from sunlight into sugars, and they have many similarities to mitochondria. The evidence suggests that these chloroplast organelles were also once free-living bacteria. The endosymbiotic event that generated mitochondria must have happened early in the history of eukaryotes, because all eukaryotes have them. Then, later, a similar event brought chloroplasts into some eukaryotic cells, creating the lineage that led to plants.

Describe the Fluid Mosaic Model

is a structure that consist of a variety of individual protein molecules moving and shifting within a fluid bilayer of phospholipids

describe the structure and functions of cell membranes

it forms a boundary between the living cells and its surrounding. Phosphlipids form a two layer sheet called a phosphlipid bilayer

explain why compartmentalization is important in eukaryotic cells

its important because it separates many parts if the cell into its own parts and jobs

Glycocalyx

provides cushioning and protection n for the plasma membrane, and important in cell recongnition

Relate the structure of the extracellular matrix to its functions

provides mechanical and structural support for tissue, regulating metabolic functions of the cells surrounded by the matrix: adhesion --> anchor cells within tissue, migration --> provides pathways, proliferation --> modulate cell growth by binding and retaining growth factors, differentiation --> influences transmission of information across the plasma membrane of the connective tissue cells

Describe a typical journey of material through the endomembrane system

the endomembrane system is a group of membranes and organelles in eukaryotic cells that works together to modify, package, and transport lipids and proteins.

Describe the four major components of the cell membrane and their functions

1. Phospholipids: make up the basic structure of the cell membrane, contains two parts a head and a tail 2. Cholesterol: made up of four rings of hydrogen and carbon atoms. they are hydrophobic and are found in the hydrophobic areas of the lipid billayer 3.protien: membrane proteins can functions as enzymes to speed up chemical reactions, act as receptors, or transport materials across the cell membrane. 4.carbohydrates: sugars, found on the extracellular side of a cell membrane together carb for m glycocalyx.

Four functional categories of organelles in eukaryotic cells

1.) Genetic Control- Nucleus and Ribosomes. 2.) Manufacturing, Distribution, and Breakdown- Rough ER, Smooth ER, Golgi Apparatus, Lysosomes, Vacuoles, Peroxisome 3.) Energy Processing- Mitochondria, Chloroplasts 4.) Structural Support, Movement, and Communication Between Cells- Cytoskeleton, Extracellular matrix, Cell junctions, Cell walls

Relate the structures of plant cell walls and plasmodesmata to their functions

An open channel in a plant cell wall through which strands of cytoplasm connect from adjacent cells. Water and other small molecules can readily pass from cell to cell.

Compare the structures of plant and animal cells

Animal cells do not have a cell wall, while plant cells do. Animal cells are circular and plant cells are rectangular. All animal cells have centrioles while they are only present in low plant forms. Animal cells do not have chloroplasts, plant cells do. Both have cytoplasm, ribosomes, mitochondria, and a nucleus.

Relate the structure of cilia and flagella to their functions

Cilia and Flagella are hairlike organelles that branch out from the surface of the cell, where they help in the movement. These organelles can be found in any eukaryotic cells. Cilia are present when there are short and large numbers of organelles on the cell. Flagella are present when there are long and few numbers of organelles on the cell.

Compare the structures and functions of chloroplasts and mitochondria

MITOCHONDRIA: is composed of two membranes, found in all cells, plants and animals, involved in aerobic respiration - it uses oxygen does not contain photosynthetic pigments, rod shaped. Chloroplast: lens shaped, contains stroma, and grana, contains photosynthetic pigments, only found in PLANT CELLS, involved in photosynthesis, it produces oxygen

Describe the evidence that suggests mitochondria evolved by endosymbiosis.

Mito:Most important are the many striking similarities between prokaryotes (like bacteria) and mitochondria: Membranes — Mitochondria have their own cell membranes, just like a prokaryotic cell does. DNA — Each mitochondrion has its own circular DNA genome, like a bacteria's genome, but much smaller. This DNA is passed from a mitochondrion to its offspring and is separate from the "host" cell's genome in the nucleus. Reproduction — Mitochondria multiply by pinching in half — the same process used by bacteria. Every new mitochondrion must be produced from a parent mitochondrion in this way; if a cell's mitochondria are removed, it can't build new ones from scratch.

distinguish between the structures of prokaryotic and eukaryotic cells

PRO: bacteria and archea nucleoid and no true organelles. EU; all other forms of life: membrane- bound nucleus and number of other organelles. bOTH: a plasma membrane and one or more chromosomes and ribosomes

The structures of prokaryotic and eukaryotic cells

Prokaryotic cells are much smaller and do not have a nucleus, while the eukaryotic cells do

explain how cells size is limited

Surface area to volume ratio. As the volume (size) of the cell increases, the surface area also increases, but the surface area increases less than the volume; so the higher the volume, the lower the surface area to volume ratio.