Biology- Module 2

Protein

• type of biomolecule

• a polymer

• Are the most numerous and versatile of the four biomolecules.

• Contain nitrogen

• creates + secretes ammonia

Carbohydrates

• type of biomolecule

• a polymer

• the second-most-versatile biomolecules

• Are simple monomer sugars and polymers of simple sugars

• crucial part of cellular respiration

• create energy

• carbon + hydrogen

Nucleic Acid

• type of biomolecule

• a polymer

• large biomolecules that play essential roles in all cells and viruses.

• Major functions of _____ _____ involve the storage and expression of genomic information (DNA and RNA); as well as, energy carriers.

Lipid

• type of biomolecule

• not polymers because their structure is not composed of a chain of monomers.

• fats, oils, and sterols

• Diverse group made up of combinations of hydrocarbons, fatty acids,

  and/or glycerol molecules

• hydrophobic

Polar molecule - Hydrophilic

• Ions and ____ _______ associate with water ______ (are water-loving)

• mix/disolve easily with water

Nonpolar molecule - Hydrophobic

• Molecules that do not associate with water (are water-hating)

• shunned by water and tend to clump together when added to water

• lipids are in this category

Phospholipid

• made up of two hydrophobic fatty acid tail bonded to a hydrophilic head containing a glycerol and a phosphate group

• an important component in cell membranes

• When exposed to water, create a _____ bilayer, a barrier that life requires

• hydrophilic AND hydrophilic

• 70% water

Phospholipid bilayer

• When exposed to water, phospholipids form a ______ ______, with the hydrophilic heads facing outward and the hydrophobic tails tucked into the interior of the ______.

• All cells are surrounded in a ______ _______, that we call the plasma membrane aka cell membrane.

Active Transport

• requires energy to pass something from one side of a cell membrane to another

Passive Transport

• does not require energy but is usually regulated by transport proteins

Endocytosis

• Large Substances Move into Cells by ______

Prokaryote

• single-celled organisms lacking a nucleus and complex internal compartments.

• example→ bacteria

• simpler cell structure

• Have: DNA, RNA, Phospholipid Bilayer, Cytoskeleton, Ribosomes, and some other parts depending on the species

Eukaryote

• may be single-celled or multicellular.

• Their cells typically possess many membrane-enclosed compartments called organelles

• Have a nucleus formed by a phospholipid bilayer

• Usually also have membrane-bound organelles with specialized jobs

• tend to be larger and their complexity allows them to form multicellular organisms.

• carry two copies of each type of chromosome

• ex. animals, fungi, plants, protists

Organelle

• lipid bilayer, membrane enclosed internal compartments.

• They concentrate and organize cellular chemical reactions.

• in eukaryotic cells

Cytoskeleton

• a roadmap that guides + allows for directed movement throughout a cell

• a network of protein cylinders and filaments

• Forms the framework of a cell

• Organizes the interior of a eukaryotic cell

• Supports the intracellular movement of organelles

• Enables whole-cell movement in some cell types, like amoebas

• Gives shape to cells without cell walls

• crucial for this coordination and use motor proteins for precise movement.

Endoplasmic Reticulum

• makes proteins

• a lipid bilayer membrane network continuous with the nuclear envelope.

• This organelle primarily makes molecules from the instructions in DNA

• two types- smooth and rough

Golgi Apparatus

• a lipid bilayer, membrane-enclosed packaging center that directs protein and lipid products from the ER to other membranes.

• send and receive components from the smooth ER

• post office, coordinates movement within a cell

Mitochondria

• use chemical reactions to transform carbohydrates into ATP in a process called cellular respiration.

  • carbs into energy

Chloroplasts

• only in plants + algae

• Capture energy from sunlight and use it to manufacture sugar molecules via photosynthesis.

• They are green

• double lipid bilayer membranes

Nucleus

• present only in eukaryotes

• the control center of the cell and protects DNA

Haploid

• AKA (n)

• Human reproductive cells

• 1 of each chromosome

  • HALF of a diploid

• present in fertilization

  • fusion of two _______ gametes results in a single diploid(zygote)

Diploid

• AKA(2n)

• 2 copies of each chromosome

• Human somatic cells

• # of each chromosome found in a cell

• a single _____ cell is a zygote

Ribosomes

• “Reads” RNA to make proteins.

• Found in both Eukaryotes and Prokaryotes.

• create most of the functional components of a cell

• rough ER is covered in ______ that make proteins for export from the cell

Binary Fission

• a process prokaryotic organisms use to reproduce.

• asexual reproduction

• prokaryotes and some single-cell protist eukaryotes

• bacteria → cell division = ____ ____

• cell replicates its DNA and splits into two genetically identical cells(daughter cells)

Cell Cycle

• a complex ____ of steps a eukaryotic cell must take to replicate and divide(to reproduce)

• Stages→ Interphase, Mitosis, Cytokinesis

• Two checkpoints: G1 + G2

• Cancer→ unnecessary + repeated ____ ____

• from moment of origin to division of two daughter cells

Interphase

• 90% of a cells life

• prepares for cell division

• Three phases: G1, S, and G2

G1 Phase

• Beginning of interphase

• First and longest phase

• prepares for DNA replication

• ______ checkpoint: First Checkpoint present where the cell cycle will stop if the cell is too small, the nutrients are inadequate, or the cell’s DNA is damaged

S Phase

• second phase of interphase

• DNA is replicated

• At the end of this phase, the cell now has twice as much DNA as normal

• chromosomes are copied and in preparation for cell division.

• New DNA and organelles produced

G2 Phase

• third phase of interphase

• after S phase, but before cell division

• increase in size, prepare for division

• _____ checkpoint: Second checkpoint stops cell cycle if the cell is too small, the

  nutrient supply is inadequate, the cell’s DNA is damaged, or when chromosome. duplication in the S phase is incomplete

• prepare for mitosis, characterized by growth

G0 Phase

• Non-replication phase or resting phase

• common in adult cells

• occurs when cells leave cell cycle

Aquaporin

• a membrane protein that allows for the passive transport of water, across the hydrophobic lipid bilayer.

• allow water to pass, but do not allow other molecules through.

Sodium-potassium Pump

• active transport → requires energy

• proteins used to move molecules AGAINST the concentration gradient (from low concentration to high concentration)

Exocytosis

• Large substances move out of cells by _____

Cell Cycle Checkpoints

• regulatory proteins enable the cell to pass through critical ____ _____ _____.

• G1 ______: Stops ___ ___ if the cell is too small, the nutrient supply is inadequate, or the cell’s DNA is damaged

• G2 ______: Stops cell cycle if the cell is too small, the nutrient supply is inadequate, the cell’s DNA is damaged, or when chromosome

  duplication in the S phase is incomplete.

• ensure that the ____ _____ does not progress if conditions are not suitable for cell division.

Mitosis

• means for asexual reproduction

• occurs after interphase in the cell cycle and before cytokinesis

• Eukaryotes use _____ to produce two identical daughter cells

• Divides nucleus into two copies

• consists of four main phases of DNA processes

  • Prophase, Metaphase, Anaphase, Telophase

• produces two genetically identical diploid cells for growth and repair

Meiosis

• is a specialized form of cell division that is needed to make gametes (sex cells)

• two rounds of Mitosis without making a new copy of DNA in between

• produces four genetically distinct haploid cells (gametes) for sexual reproduction

Cytokinesis

• the process of dividing the parent cell’s cytoplasm to produce two daughter cells.

• last step in the cell cycle before it repeats.

Prophase

• first phase of mitosis

• forms road networks to transfer DNA

• nucleus breaks down and begins to attach to the cytoskeleton

• Two cytoskeletal structures called centrosomes begin to move toward opposite ends of the cell

Metaphase

• “meet in the middle” phase

• chromosomes meet in the center of the cell

• ensures each new cell gets the half of the chromosomes

Anaphase

• chromatids are pulled apart

• one copy goes to each side

• once separated, each chromatic is considered a new chromosome

Telophase

• Nuclear envelopes begin to form around the two new sets of chromosomes at each end of the cell

• Within each nucleus, the chromosomes decondense, as each

  new daughter cell begins its G1 phase(restart cell cycle)

Gametes

• sex cells

• Meiosis results in ______ that will mature into eggs or sperm.

• contains a single set of chromosomes (haploid)

Germ-line Cells

• the sex cells—sperm in males and eggs in females—that pass genetic material from one generation to the next

• only cell that undergoes meiosis

• produces gametes or sex cells

Motor Proteins

• responsible for precise movement

• use energy to "walk" along cytoskeletal filaments for cargo transport