Biology Exam 2 Part 2

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Membrane transport

Membrane transport

substances must travel through the plasma membrane

Substances want

equilibrium

Plasma Membrane

phospholipid bilayer is differentially permeable

Passive Transport

movement of molecules without energy

diffusion

passive transport from an area of high concentration to low concentration

Facilitated Diffusion

transport proteins help move hydrophilic and charged particles across the membrane (High to Low)

Osmosis

diffusion of water across a membrane from high to low concentration (of the water)

How does water move if a cell is placed in saltwater (saltwater is saltier than the water in the cell)

Osmosis will cause water to move out of the cell

Osmosis

diffusion of water across a membrane from high to low concentration

Aquaphorins

special proteins that help water cross the membrane faster/easier

Does water require aquaphorins to cross the membrane?

NO

What describes the active transport of potassium?

K+ will move from low to high concentration, energy is used

Active transport

uses energy to take things from low to high concentration

Exocytosis

a membrane bound vesicle fuses with the membrane and expels the large molecule outside the cell

Endocytosis

a vesicle pinches the plasma membrane inward, and brings a large molecule into the cell

Nutrient

substance in food that provides structural materials or energy

Macronutrients

nutrients required in large amounts

Do humans get half our water from our food?

yes

How much percent water are humans?

78-43% water (declines with age)

Carbohydrates

main energy source, ex. bread, cereal, rice, pasta

Digestion of Carbohydrates

simple sugars: digested easy complex carbohydrates: digested slowly

Healthy diet

carbs should mostly be complex carbohydrates

Whole food

unprocessed food not stripped of nutrition

Processed food

processing, refining, grinding

Furver (roughage)

indigestible. complex carbohydrates, some digested by bacteria in large intesting

Proteins

parts of cellular structures and processes, ex beef, eggs, gluten

Protein structure

polymers of amino acids

Essential Amino Acids

cannot be made in the body, must get from food

Nonessential amino acids

made in body

Complete protein

contains ALL of the essential amino acids

A fatty acid tail contains carbon that is double bonded to another carbon, what fat has this structure?

Unsaturated fat

Fats

source of stored energy, ex. milk, cheese, insulates body and organs

Fat structural composition

3 carbon skeleton attacked to 3 fatty acid tails

Essential Body Acids

cannot be made in the body, ex omega 3

Saturated Fat

fatty acid carbon bond to as much hydrogen as possible, solid at room temp. ex. animal fats

Saturated Fats

fewer hydrogens are bound to carbons, liquid at room temp, ex. plant fats

Polyunsaturated fats

many double bonds

Hydrogenation

process adds hydrogen atoms to solidify unsaturated fats(ex. oils), ex margarine,

Trans Fat

produced by incomplete hydrogenation, double bonds are flat and not kinked, increased health risks

What vitamin can be synthesized by the human body?

Vitamin D

Micronutrients

required in small quantities, two types; vitamins and minerals, not broken down by the body

Vitamins

organic substances that mostly cannot be synthesized by the body

Fat Soluble

stored in fat, excess accumulation can be toxic

Minerals

inorganic substances (no carbon)

Minerals are:

water soluble, supplied through diet, essential, ex. calcium, magnesium

Calcium

commonly supplemented mineral, needed for blood clotting

Antioxidants

electron donor molecule, prevent cell damage

Metabolism

all chemical reactions occurring in the body

How do enzymes affect metabolic reaction?

Enzymes decrease the activation energy of a reaction

Enzymes

proteins that catalyze(speed up) chemical reactions, end in suffix -ase

Activation energy

energy required to start a metabolic reaction

Substrate

chemical being metabolized

Active site

enzyme region where substrate binds

Enzyme Specificity

each enzyme catalyzes a particular reaction bases on enzyme shape and active site shape

Metabolic Rate

measure of a person's energy use

basal metabolic rate

the energy use of a resting, wakeful animal, human is 1680 calories a day

What influences BMR?

exercise, bio sex, age, genetics

What part of this structure will be removed to release energy?

to the last negatively charged phosphate

Cellular Respiration

series of metabolic reactions converting food energy to a usable form and releasing waste products

Adenosine Triphosphate (ATP)

provides energy to drive processes in living cells

Phosphorylation

phosphate group transferred from ATP to ADP

What is the ADP and ATP battery analogy?

ADP: low battery ATP: full battery

Whats is the equation for cellular respiration?

glucose + oxygen = carbon dioxide + water, C6H12O6+6O2=6H2O+6CO2

Cellular respiration

requires oxygen from breathing; releases carbon dioxide for delivery to lungs for exhalation

Aerobic Respiration

occurs mostly in the mitochondria, series of complex directions

NAD+

taxicab for electrons

NAD+ is

empty, no electrons or hydrogen

NADH is

full of electrons and hydrogen

What are the three stages of cellular respiration?

1. Glycolysis

2. Citric acid cycle

3. Electron transport chain and ATP synthesis

What step of the cellular respiration does not require oxygen?

Glycolysis

Glycolysis

6 carbon molecules broken down into two pyruvic acid molecules, occurs in cytosol, doesn't need oxygen

After Glycolysis

pyruvic oxidation happens, 2 carbon fragment metabolized inside mitochondria

Citric Acid Cycle

series of enzyme catalyzed reactions in the mitochondrial matrix

What does the Citric Acid Cycle produce?

Produces 4ATP and 10 NADH

H+ and ATP synthase

26 ATP molecules synthesized, each NADH yields ~2.5 ATP

What is an inaccurate description of what happens in the electron transport chain and ATP synthesis?

Water molecules are dropped off by NADH and used by membrane proteins

If carbohydrates are unavailable

fats will be uses

If carbohydrates and fats are unavailable

protein will be uses

Why does lactic acid build up in muscle cells during intense exercise?

Oxygen is less available as an electron acceptor

Anerobic respiration

metabolic process to generate energy without oxygen

Fermentation

one process cells use to produce energy without oxygen