Bio Exam 2

4. Nutrition, Enzymes, Metabolism 6. Dietary Energy & Cellular Respiration 24. Plant Growth and Reproduction 25. Plant Physiology

NEAT

Non exercise Activity Thermogenesis

Body Mass Index

BMI

-estimates body fat based on height and weight

How do we measure food energy?

Calories and calories

Calories

–equal to 1,000 calories, or 1 kilocalorie (kcal)

calories

–the amount of energy required to raise the temperature of 1 g of water by 1°C

How does the body use macromolecules in food?

The body digests macromolecules into building blocks or subunits.

The body uses these subunits:

–to make new molecules.

–as sources of energy.

How much stored energy are in each macromolecule?

Fat: 9 C/g

Protein and carbohydrate: 4 C/g

Nucleic acids: not a significant source of stored energy

Balanced Intake and Use of Energy

-A healthy diet includes balancing calories from food with calories burned.

-An imbalance of energy in and out can lead to weight gain or weight loss.

NEAT includes:

-daily activities such as shopping, yard work, walking your dog.

To use energy from food

we need to convert it to energy

Food must be

broken down into its component subunits(fats and sugars)

-breakdown products must go through a series of biochemical reactions that convert the chemical energy stored into a form of fuel we can use.

ATP

adenosine triphosphate

-our cells use atp to carry out energy requiring functions

The most commonly used to convert food into energy

ATP

Aerobic Respiration

A series of reactions that convert stored food into ATP

-occurs in the presence of oxygen

-our cells use the oxygen we inhale to help extract energy from food. the cells convert the energy stored in food molecules into the bonds of ATP, the cell’s energy currency.

When cells need energy

-they break bonds that make up ATP, releasing stored energy, which can then participate in chemical reactions

-ATP is spent any time a muscle contracts or a neuron fires.

Blood Transport ___ from food and ___ from the lungs.

Cell releases energy from ____ and captures it into ___.

Blood transports excess ____ to the lungs and ____ to the kidneys.

-glucose & oxygen

-glucose & ATP

-carbon dioxide & water

What are the three stages of Aerobic Respiration?

1.Glycolysis

2.Citric Acid Cycle

3.Electron Transport Chain

Glycolysis

occurs in the cytoplasm(outside the cell)

-series of reactions that breaks down sugar into smaller units(pyruvate)

-produces 2 ATP

Citric Acid Cycle

occurs inside the cell

-series of reactions that help extract energy(high energy electrons) from food

-NAD⁺ picks up and transfers electrons

-eleases carbon dioxide

-produces 2 ATP

Electron Transport Chain

occurs inside the cell

-NAD+ molecules bring electrons to folds on the inner membrane of the mitochondria

-Electrons flow down a chain of molecules on the inner membrane of the mitochondria

-At the end of the chain, oxygen accepts the electrons and combines with hydrogen atoms to form water.

-The flow of electrons powers the production of most of the ATP in aerobic respiration.

-produces 26-28 ATP

With no oxygen. aerobic respiration stops, and an anaerobic process called

fermentation begins

Fermentation

products undergo fermentation in the cytoplasm instead of aerobic respiration in mitochondria

products:

lactic acid, alcohol, small amount of ATP

Animals store extra energy as

-glycogen in muscle and liver cells

-triglycerides in fat cells

Glycogen

-a complex carbohydrate which is made up of linked chains of glucose molecules

-glycogen is used in our body as short term energy storage

Triglycerides

-type of lipid found in fat cells

-converts fat, amino acids, and sugars into triglycerides

-triglycerides are used for long-term energy storage

Energy is

never destroyed, it is only converted from one form to another

-photosynthesis and respiration form a continuous cycle, with the outputs of one process serving as the inputs of the other

Macronutrients

nutrients that organisims must ingest in large amounts to maintain health

-carbohydrates, proteins, lipids, and fats

Micronutrients

are also required by organisms but in much smaller amounts than macronutrients

-vitamins and minerals

-important to maintain health

-play structural and functional roles in the body

If you are starving what does the body burn first?

carbs

fats

proteins

Global body temperature

97 f

Malnutrition

a medical condition resulting from the lack of essential nutrients in the diet

Components of Food

Nutrients & Energy

Nutrients

the chemical building blocks need to live, grow, and repair themselves

-provides energy

Energy

the ability to do work

-powers our activities

-build complex muscles

A varied diet must include

vegetable, oils, grains, meats, and dairy products and the proportion of each one varies

-most plant products contain more carbohydrates than protein

-animal products contain more protein per gram than carbohydrates

Marconutrients are

large molecules

-provides our cells with building blocks for macromolecules

-macronutrients from our diet are broken down into smaller units beginning with digestion.

-the body uses these subunits as building blocks or energy

Macromolecule: Carbohydrates

broken down into simple sugars

used to build cell surface markers, energy storage molecules

Macromolecules: Proteins

broken down into amino acids

used to assemble new proteins that have many different functions in the body

Macromolecules: Fats

broken down into fatty acids and glycerol

-used to build molecules that form cell membranes

Nucleic Acids

-not macronutrients because they are provided in smaller amounts

-broken down into individual nucleotides

-used to build DNA and RNA

Essential Nutrients

-cells cannot synthesize them

-nutrients that must be obtained through diet

Essential Amino Acids

20 amino acids used to build proteins

-9 cannot be synthesized

Some nutrients our bodies cannot be manufactured

and must be obtained pre assembled from our diet.

Ready to use therapeutic foods

RUTF

What is digestion?

Process of breaking down huge food molecules into smaller pieces so that our bodies can use them

-series of chemical reactions to break the bonds that hold food molecules together

-starts in the mouths and continues throughout the digestive system

Metablosim

all chemical reactions occuring in the body

-requires the assistance of helper molecules called enzyme

Catabolic Reactions

break down larger structures to smaller ones(bond breaking)

Anabolic Reactions

build new structures from smaller subunits(bond building)

Enzyme

proteins that catalyzes(speeds up) a chemical reaction

Substrate

molecule to which an enzyme binds and on which it acts

Active Site

part of an enzyme that binds to the substrate

How enzymes catalyze reactions

enzymes reduce activation energy for chemical reactions, so they happen much quicker

Activation energy

the energy required for a chemical reaction to proceed.

-is the energy that must be put into a reaction in order to make it “go“. enzymes reduce the activation energy in both anabolic and catabolic reactions, making them occur more rapidly.

Minerals

inorganic elements required by organisms for normal growth, reproduction, and tissue maintenance

ex:

-calcium

-iron

-zinc

-potassium

Vitamins

organic molecules required in small amounts for normal growth, reproduction, and tissue maintenance

Vitamins and minerals

are structural roles

Minerals act as

cofactors

-inorganic micronutrients required to activate an enzyme

-zinc, copper, and iron

Vitamins act as

coenzymes

-small organic molecules required to activate enzymes

Balanced Diet

nutritionists recommend that fruits, vegetables, and whole grains make up the largest portion of our diet

Amalyse

breaks down complex carbohydrates

Vitamin A

helps vision

ex: carrots

Vitamin B

helps convert food into energy

-vitamin b12, and 6

Vitamin C

helps make collagen and make skin

ex: citrus fruits

Vitamin D

helps bones

ex: milk

Vitamin E

help skin

Blue is high frequency

more energy and compact

What is the advantage of enzymes?

it does not get consumed during the reaction and the energy cost is lower and activation energy is lower

California Redwoods

The tallest plants on Earth.

Root System

The underground part of a plant that absorbs water and nutrients and grows downward.

Shoot System

The aboveground part of a plant that includes stems and leaves and grows upward.

Cell Wall

A rigid layer surrounding the cell membrane of some cells, providing shape and structure.

Central Vacuole

A fluid-filled compartment in plant cells that contributes to cell rigidity by exerting turgor pressure against the cell wall.

Chloroplast

The organelle in plant cells where photosynthesis takes place.

Lignin

A hard, durable material that forms inner cell walls and makes plant tissues woody.

Xylem Cells

Spirals of lignin that strengthen the inner cell wall of vascular cells (xylem).

Turgor Pressure

Water pressure exerted by the central vacuole that keeps the plant upright.

Vascular System

Tube-shaped vessels and tissues that transport fluids, such as water and sugar, throughout an organism's body.

Xylem

The part of the vascular system that transports water from the roots up the stem and through the veins of the leaves in one-way tubes.

Phloem

The part of the vascular system that transports sugars in a two-way direction.

Cuticle

A waxy coating on leaves and stems that prevents water loss.

Stomata

Pores on leaves that allow for the exchange of oxygen and carbon dioxide and allow water to evaporate.

Apical Meristem

The site of growth for stems, leaves, and flowers, causing primary growth and making the plant taller.

Lateral Meristem

The site of growth for secondary growth, contributing to stems increasing in width and becoming woody.

Wood

The secondary growth of xylem tissue that produces tree rings and increases trunk diameter.

Carnivorous Plants

Plants that acquire scarce nutrients by digesting insects and other small animals.

Autotrophs

Organisms, including plants, that produce carbohydrates from carbon dioxide and water through photosynthesis.

Nitrogen Fixation

The process of converting atmospheric nitrogen into a form that plants can use, aided by symbiosis.

Chlorophyll

The dominant pigment of photosynthesis that reflects green wavelengths, making plants look green.

Xanthophyll and Carotene

Lesser photosynthetic pigments that capture additional wavelengths of light and expand the range of light effective for photosynthesis.

Phototropism

The growth of the stem of a plant toward light.

Gravitropism

The growth of plants in response to gravity, with roots growing downward and shoots growing upward.

Thigmotropism

The growth of plants in response to touch, causing vines to wrap around structures or carnivorous plants to spring closed to catch insects.

Ethylene

A gaseous plant hormone that promotes ripening and is produced by ripe plants.

Gibberellins

Plant hormones that promote stem elongation, cell division, and germination.

Abscisic Acid

A plant hormone that promotes dormancy and decreases as plants grow.

Poisonous Plants

Plants that defend themselves against herbivores through waxy coatings and poisons that can kill or repel animals.

Key Structural Features of Plants

Cell walls made of tough cellulose, central water-filled vacuoles, and a vascular system for water and nutrient transport.

Transpiration

The process of water transport powered by evaporation through stomata in leaves.

Primary and Secondary Growth

Plants undergo primary growth (vertical) and secondary growth (horizontal) as a result of cell division in meristems.

Adaptations to Coping with Limiting Nutrients and Harsh Conditions

Plants have various adaptations such as nutrient acquisition through symbiosis, carnivory, and the ability to respond to environmental cues.1. Autotrophs:Organisms, such as plants, that can produce their own food through photosynthesis.