Biology 1010 - Spence

What are the 4 Emergent Properties of Water?

1. Cohesive behavior 2. Ability to moderate temperature 3. Expansion upon freezing 4. Versatility as a solvent

What is the relevance of water's high specific heat to life on Earth?

A large body of water can absorb & store a huge amount of heat from the sun during the summer while warming up only a few degrees. That's why air temperatures are lower near the coast (compared to inland), yet the water temperatures are still mild. Water's high specific heat helps it maintain temperatures during the winter, too. During the winter, the gradually cooling water can warm the air, so that air is warmer near the coast compared to inland. The high specific heat of water also tends to stabilize ocean temperatures, creating a favorable environment for marine life.

Nucleic Acids

A nucleic acid serves as a blueprint for proteins & through the actions of proteins, for all cellular activities. Two types of nucleic acids are RNA & DNA.

What is the Golgi Apparatus?

After leaving the ER, many transport vesicles travel to the golgi apparatus. Think of the golgi apparatus as a post office for receiving, sorting, modifying, and shipping proteins. A golgi stack has a functional directionality, with a cis face that receives vesicles containing ER products & a trans face that dispatches vesicles.

What is the endoplasmic Reticulum (ER)?

An extensive network of membranes that is continuous with the nuclear envelope Smooth ER lacks ribosomes; functions in diverse metabolic processes, which vary by cell type (ex. lipid synthesis, carbohydrate metabolism, etc.) Rough ER is studded with ribosomes; is involved in protein production (ribosomes) & synthesizes secretory proteins, which depart from the ER in transport vesicles

What are Chloroplasts?

Are found in leaves & other green organs of plants & in algae Contain the green pigment chlorophyll, along with enzymes & other molecules that function in the photosynthetic production of sugar Has 3 compartments: Intermembrane space Thylakoid space Stroma (contains free ribosomes & chloroplast DNA molecules) This compartmental organization allows the chloroplast to convert light energy to chemical energy during photosynthesis.

What are the 4 major classes of molecules?

Carbohydrates Lipids Proteins Nucleic acids

Explain, Carbohydrates?

Carbohydrates include sugars & polymers of sugars. The simplest carbohydrates are monomers called monosaccharides, or simple sugars. Disaccharides are double sugars, consisting of 2 monosaccharides joined by a covalent bond. Carbohydrate macromolecules are polymers called polysaccharides, composed of many sugar building blocks.

Cohesive Behavior

Cohesive behavior Water molecules stay close to each other as a results of hydrogen bonding. These linkages make water more structured than most other liquids. Collectively the hydrogen bonds hold the substance together, a phenomenon called cohesion.

What is a Nucleus?

Contains most of the genes in the eukaryotic cell Directs protein synthesis by synthesizing mRNA mRNA = messenger RNA Remember, DNA is used to synthesize mRNA, which is then used to synthesize proteins. DNA is organized into discrete units that carry this genetic information called chromosomes. Each chromosome contains one long DNA molecule associated with many proteins. The complex of DNA & proteins is called chromatin. The zoomed-in segment of a chromosome from a non-dividing cell shows two states of coiling of the DNA (blue) & protein (purple) complex. The thicker form is sometimes organized into long loops.

What is the control group?

Control group: does not receive the test variable (unchanged) EXAMPLE: In the mice experiments, the control group is always the camouflaged group (the light mouse in the beach habitat and the dark mouse in the inland habitat), because these mice are NOT spray painted (so they DON'T receive the test variable).

What is the Dependent variable?

Dependent variable: the factor being measured that is predicted to be affected by the independent variable (predict it DEPENDS on the independent variable) EXAMPLE: The dependent variable for these experiments is the predation rate, since it is being MEASURED + it's predicted that it DEPENDS on the independent variable.

What is some more Nucleus stuff?

Enclosed by a nuclear envelope, which separates its contents from the cytoplasm is a double membrane is perforated by nuclear pores Contains a nucleolus, which synthesizes rRNA & assembles ribosomal subunits Continuous with the endoplasmic reticulum (ER)

What is Energy?

Energy is the capacity to cause change - for instance, by doing work.

What are Fats?

Energy storage! 1 g of fat stores more than twice as much energy as 1 g of polysaccharide Despite this fact, plants store their energy as a polysaccharide (carbohydrate), because they are relatively immobile. Animals, however, are mobile, so they store their fuel as fat in adipose cells since it's more compact (less weight to carry around). Since plants are immobile, they don't have to worry about the fact that they are carrying TWICE as much weight to carry around the SAME amount of energy. However, humans want to store energy as EFFICIENTLY as possible & with minimum weight, because we are mobile.

What is the Experimental group?

Experimental group: receives the variable being tested (changed) EXAMPLE: The experimental group for these experiments is the non-camouflaged mice (the dark mouse in the beach habitat and the light mouse in the inland habitat), because these mice are spray painted (so they DO receive the test variable).

Ice floats on liquid water. Why is this relevant to life on Earth?

If ice sank, then eventually all ponds, lakes, & even oceans would freeze solid, making aquatic life as we know it impossible on Earth. Instead when a deep body of water cools, the floating ice insulates the liquid water below, preventing it from freezing & allowing life to exist under the frozen surface.

What is the Independent variable?

Independent variable: the factor being manipulated EXAMPLE: In the mice experiments, the color of the mouse fur is the independent variable, because it is being manipulated (the mice are spray painted).

What is Kinetic Energy?

Kinetic energy is the energy of motion.

What are Lipids?

Not large enough to be considered macromolecules Are grouped together because they share one important trait: they mix poorly (if at all) with water. Include waxes & certain pigments, but we will focus on the types of lipids most important biologically: Fats Phospholipids Steroids

What is the mitochondria?

Ovoid or elongated organelles that are called the "powerhouses" of the cell because they are the sites of ATP synthesis by cellular respiration Have two membranes: a smooth outer membrane & an convoluted inner membrane that has numerous partition-like folds called cristae These folds increase the surface area of the inner membrane to facilitate chemical reactions. The mitochondrial matrix (inside the inner membrane) contains free ribosomes, mitochondrial DNA, & the enzymes that catalyze cellular respiration.

What is the Plasma Membrane?

The boundary of the cell that is selectively permeable, allowing the passage of some substances while blocking the passage of other substances. Remember, FUNCTION follows FORM. Thus, the structure of the plasma membrane allows this vital function to occur. Specifically, the plasma membrane is a double membrane layer composed of phospholipids

Validity

The quality of being logically or factually sound Refers to the credibility or believability of the research Asks the questions "Are these research results accurate?"

Describe Versatility as a solvent Property of water.

Water can easily dissolve many substances.

Describe expansion upon freezing property of water.

Water is one of the few substances that are less dense as a solid than a liquid. AKA: Ice floats on liquid water.

Describe the Ability to Moderate Temperature.

Water moderates air temperature by absorbing heat from air that is warmer & releasing the stored heat to air that is cooler.

The ability of water to stabilize temperature stems from its relatively high specific heat.....What does this mean?

Water's high specific heat means it can absorb or release a relatively large amount of heat with only a small change in its own temperature.

What are Lysosomes?

a membrane-enclosed sac of hydrolytic enzymes that digest (hydrolyze) macromolecules Carry out intracellular digestion of macromolecules in a variety of ways: Food vacuoles are formed from phagocytosis as materials are taken into the cell, & lysosomes fuse with these vacuoles to digest these materials. Carry out intracellular digestion of macromolecules in a variety of ways: During autophagy, a damaged organelle becomes surrounded by a double membrane, & a lysosome fuses with this vesicle to digest & recycle the cell's own organic material.