The Cell : Structure and Function

Carbohydrates

Carbohydrates

Serves as fuel and building material

Monosaccharides

(e.g. sugar) is the basic unit of Carbohydrates.

Disaccharides

consists of two monosaccharides joined by a glycosidic linkage

Polysaccharides

are macromolecules, polymers with a few hundred to a few thousand monosaccharides joined by glycosidic linkages

Lipids

are a diverse group of hydrophobic molecules

Phospholipids

are essential for cells and made up 2 fatty acids (hydrophobic end) and glycerol (hydrophilic end)

Steroids

are lipids characterized by a carbon skeleton consisting of four fused rings.

Cholesterol

a crucial molecule in animals especially in cell membranes

Proteins

include a diversity of structures, resulting in a wide range of functions.

amino acids & polypeptides

Amino Acids

basic unit of proteins

Polypeptides

amino acid polymers

Four

How many protein structures are there?

Primary Structure (Proteins)

linear chain of amino acids

Secondary Structure

regions stabilized by hydrogen bonds between atoms of polypeptide backbone

Tertiary Structure

are 3-dimensional shape stabilized by interactions between side chains.

Quaternary Structure

the association of 2 or more polypeptides

Nucleic Acids

store, transmit, and help express hereditary information

DNA & RNA

Two Types of Nucleic Acid

DNA

Deoxyribonucleic Acid ▪ The DNA molecule is usually double helix.

RNA

Ribonucleic Acid ▪ The tRNA molecule has roughly L-shaped structure.

Prokaryotic (Bacteria) Cell & Eukaryotic Cell (Animal Cell)

Two Types of Cells

Plasma membrane

selective barrier that allows sufficient passage of oxygen, nutrients, and waste to service the volume of every cell.

Nucleus

contains most of the cell’s genes and is usually the most conspicuous organelle

Pores

regulate the entry and exit of molecules from the nucleus

Chromosomes

where DNA is organized into discrete units called

Chromatin

DNA and proteins of chromosomes are together called

Nucleolus

located within the nucleus and is the site of ribosomal RNA (rRNA) synthesis

Ribosomes

complexes made of ribosomal RNA and protein

Endoplasmic reticulum (ER)

accounts for more than half of the total membrane in many eukaryotic cells

Smooth and Rough ER

Two distinct regions of ER

Golgi apparatus

consists of flattened membranous sacs called cisternae ; functions include Modifies products of the ER ➢ Manufactures certain macromolecules ➢ Sorts and packages materials into transport vesicles

Lysosome

membranous sac of hydrolytic enzymes that can digest macromolecules

Endomembrane System

a complex and dynamic player in the cell’s compartmental organization

Mitochondria

are in nearly all eukaryotic cells. • They have a smooth outer membrane and an inner membrane folded into cristae

Peroxisomes

specialized metabolic compartments bounded by a single membrane.

Perixosomes

produce hydrogen peroxide and convert it to water

Cytoskeleton

a network of fibers that organizes structures and activities in the cell

Microfilaments , Microtubules , Intermediate Filaments

The Three Type of molecular structures that consist of the cytoskeleton

Cytoskeleton

helps to support the cell and maintain its shape

Cytoskeleton

interacts with motor proteins to produce motility

Vesicles

travel along tracks provided by the cytoskeleton.

Microtubules

control the beating of flagella and cilia, microtubule-containing extensions that project from some cells

Microfilaments

that function in cellular motility contain the protein myosin in addition to actin

Cell Junctions

Neighboring cells in tissues, organs, or organ systems often adhere, interact, and communicate through direct physical contact.

Tight Junctions, Desmosomes, & Gap Junctions

3 types of cell junctions common in epithelial tissue

Desmosomes

(anchoring junctions) fasten cells together into strong sheets

Gap Junctions

(communicating junctions) provide cytoplasmic channels between adjacent cells.

Tight Junctions

membranes of neighboring cells are pressed together, preventing leakage of extracellular fluid

Ribosomes

site of protein synthesis ; carry protein into cytosol, outside nuclear envelope / endoplasmic reticulum

Mitochondria

generate most of the energy to be used